Monolithic Photoelectrochemical Device for Direct Water Splitting with 19% Efficiency
- Wen-Hui ChengWen-Hui ChengDepartment of Applied Physics and Material Science, California Institute of Technology, Pasadena, California 91125, United StatesJoint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United StatesMore by Wen-Hui Cheng,
- Matthias H. RichterMatthias H. RichterJoint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United StatesDivision of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United StatesMore by Matthias H. Richter,
- Matthias M. May*Matthias M. May*E-mail: [email protected] (M.M.M.).Department of Chemistry, University of Cambridge, CB2 1EW Cambridge, United KingdomHelmholtz-Zentrum Berlin für Materialien und Energie GmbH, Institute for Solar Fuels, D-14109 Berlin, GermanyDepartment of Physics, Technische Universität Ilmenau, D-98693 Ilmenau, GermanyMore by Matthias M. May,
- Jens OhlmannJens OhlmannFraunhofer Institute for Solar Energy Systems ISE, D-79110 Freiburg, GermanyMore by Jens Ohlmann,
- David LacknerDavid LacknerFraunhofer Institute for Solar Energy Systems ISE, D-79110 Freiburg, GermanyMore by David Lackner,
- Frank DimrothFrank DimrothFraunhofer Institute for Solar Energy Systems ISE, D-79110 Freiburg, GermanyMore by Frank Dimroth,
- Thomas Hannappel*Thomas Hannappel*E-mail: [email protected] (T.H.).Department of Physics, Technische Universität Ilmenau, D-98693 Ilmenau, GermanyMore by Thomas Hannappel,
- Harry A. Atwater*Harry A. Atwater*E-mail: [email protected] (H.A.A.).Department of Applied Physics and Material Science, California Institute of Technology, Pasadena, California 91125, United StatesJoint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United StatesMore by Harry A. Atwater, and
- Hans-Joachim LewerenzHans-Joachim LewerenzJoint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United StatesDivision of Engineering and Applied Science, California Institute of Technology, Pasadena, California 91125, United StatesMore by Hans-Joachim Lewerenz
Abstract
Efficient unassisted solar water splitting, a pathway to storable renewable energy in the form of chemical bonds, requires optimization of a photoelectrochemical device based on photovoltaic tandem heterojunctions. We report a monolithic photocathode device architecture that exhibits significantly reduced surface reflectivity, minimizing parasitic light absorption and reflection losses. A tailored multifunctional crystalline titania interphase layer acts as a corrosion protection layer, with favorable band alignment between the semiconductor conduction band and the energy level for water reduction, facilitating electron transport at the cathode–electrolyte interface. It also provides a favorable substrate for adhesion of high-activity Rh catalyst nanoparticles. Under simulated AM 1.5G irradiation, solar-to-hydrogen efficiencies of 19.3 and 18.5% are obtained in acidic and neutral electrolytes, respectively. The system reaches a value of 0.85 of the theoretical limit for photoelectrochemical water splitting for the energy gap combination employed in the tandem-junction photoelectrode structure.
Electrochemical water splitting was achieved by van Trostwijk and Deiman in 1789 and, about a decade later, by Nicholsen and Carlisle,(1,2) whereas light-induced unassisted water splitting with rutile as a photoanode was reported in 1972, resulting in a small but measurable efficiency.(3) Efficient solar water splitting was first achieved using a dual-junction tandem photoelectrode(4) under a light intensity equivalent to 11 suns.
In 2015, several devices with solar-to-hydrogen (STH) efficiency greater than 10% at 1 sun illumination were reported,(5) and in 2017, an efficiency of 16.2% was achieved.(6) Overall, advances in solar water splitting(1) have led to a number of functional prototypes of photoelectrochemical and photoelectrosynthetic cells in recent years,(2) featuring improved photoelectrode stability through the use of corrosion protection layers.(7,8) However, comparison of STH efficiencies realized so far with theoretical limiting efficiencies(9) shows considerable room for further improvement; at present, the highest-efficiency systems reach about 2/3 of the theoretical limiting value for a given photoelectrode. To enable STH efficiencies approaching theoretical limits, the photovoltage has to be as large as possible, which requires a minimized photoelectrode dark current. This in turn dictates that the charge carrier recombination at interfaces must be prevented. To maximize the photocurrent, a reduction of the photoelectrode surface reflectivity under operating conditions is also required, as is mitigation of light absorption in the catalyst layer applied to the photoelectrode surface.(10)
If one utilizes the band gap combination of a given tandem photoelectrode and the best reported exchange current densities for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) and omits losses due to external radiative efficiency (ERE) defined as the portion of radiative recombination to the total (radiative and nonradiative) recombination and solution resistance, the realistic limiting STH efficiencies can be calculated.(9) For the tandem photoelectrode used here (see Supporting Information section S1), this value is 22.8%. Approaching such limiting efficiencies provides a clear objective for a renewable fuels technology because inclusion of hydrogen in the existing worldwide fuel generation infrastructure could enable direct and widespread application of renewable fuels in the transportation sector and for electricity generation.(11)
Here, we demonstrate an approach to achieving efficiencies near the theoretical limits for the photoelectrode energy band gaps employed. A key aspect of our approach is (i) the use of a crystalline anatase TiO2 photocathode interfacial layer (see Supporting Information section S3), deposited by atomic layer deposition (ALD), to facilitate reduced reflectivity and interface recombination velocity and (ii) a size distribution and spatial arrangement of Rh catalyst nanoparticles (NPs) tailored to achieve ultralow light attenuation. The crystalline anatase TiO2 interlayer shows excellent energy band alignment with the tandem window layer and its interfacial ultrathin oxidized surface part and with the electrolyte. In addition, it serves as an efficient antireflection coating and as a support for the catalyst NPs, with enhanced adhesion relative to III–V compound semiconductor surfaces.
We employ a dual-junction tandem photoelectrode where the high-band-gap subcell thickness has been increased for better current matching and the transparency of the tunnel diode was improved.(10,12,13) To further increase the STH efficiency, interfacial layers have been designed to reduce charge carrier recombination and to increase optical light coupling into the photoelectrode absorber layers. The surface conditioning sequence resulted in etching of the GaAs cap layer by an NH4OH–H2O2–H2O solution, leaving an oxidized surface layer (AlInPOx) on top of the n+-doped AlInP window layer (see Supporting Information section S1). A crystalline anatase TiO2 film with an effective thickness of 30 nm was deposited to act as a corrosion protection layer and an antireflection coating, as well as serving as a conducting substrate surface for photoelectrodeposition of Rh NP electrocatalysts. The Rh NPs exhibited large surface areas and thus high exchange current and, simultaneously, particularly low light attenuation. The photocathode device configuration employed is generally less prone to photodecomposition than photoanode devices, where charge carriers with high oxidation potential are present at the semiconductor surface. Figure 1 shows a schematic of the resulting device: the photoelectrode consisting of GaInP and GaInAs subcells on a GaAs substrate, an anatase TiO2 protective layer, the Rh NP catalyst layer, and a sputtered RuO2 counter electrode (OER) are depicted. Also depicted on the side of the layer structure in Figure 1 is an energy band diagram under illumination where the quasi-Fermi levels show the splitting for electrons and holes necessary to achieve unassisted water splitting (see Supporting Information section S4). The surface of the crystalline TiO2 film illustrated in Figure 1b indicates a continuous film with height variations, seen by AFM, that give it a flake-like appearance. Figure 1c illustrates the protocol for pulsed photoelectrodeposition of Rh catalyst NPs (see Supporting Information section S1), and the inset gives SEM and AFM images of the Rh NPs. Figure 1c depicts the procedure to obtain the highest-activity catalysts at almost negligible light attenuation; fine control of particle size smaller than 20 nm was achieved by careful adjustment of the electrode potential, enabling considerably higher catalyst loading compared to that of a dense film of equivalent catalyst loading deposited by conventional vapor-phase or electrochemical reduction. This procedure facilitates photocathodes with high-transparency catalysts, which maintain high photocurrent densities and result in increased efficiency, which is determined from the relation
(1)
Figure 1
Figure 1. Functionalization of a dual-junction tandem as the photoelectrode for unassisted water splitting: (a) schematic of the device structure after functionalization with interfacial films and electrocatalysts (see text); (b) topography of the crystalline anatase TiO2 layer by HRSEM and AFM; (c) protocol of the photoelectrodeposition of Rh NPs; the arrow shows the potential used for stroboscopic deposition under white light illumination, as shown in the upper left inset. The potential choices made are indicated by black dots; the best result was obtained for E = +0.3 V vs SCE. Resulting Rh particles are shown in the inset under the J–V characteristic (upper image: SEM; lower one: AFM). The potential control and corresponding particle size distribution are included in Supporting Information section S1. The root-mean-square surface roughness of TiO2 is 6.3 and 3.6 nm (with/without Rh, respectively).
The solar fuel generator efficiency ηSTH is given by the operating current at the counter electrode potential, the thermodynamic value for the reaction (Erxn = 1.23 V for water splitting under standard conditions), and the reaction Faradaic efficiency fFE, determined by gas product analysis measurements.
Electronically, the photoelectrode configuration used here facilitates alignment of the conduction bands of the AlInP window layer of the tandem photoelectrode to the indium oxide and indium phosphate layers (created by the cap layer etching process) and the anatase TiO2 protection/antireflective layer. We note that photogenerated electrons, which are minority carriers in the main part of the tandem subcells, become majority carriers in the AlInP and TiO2 layers, reducing recombination losses in carrier transport. Details of the energy band alignment and the photoelectron spectroscopy and optical data used to support it are described in the Supporting Information section S4. In addition, the large valence band offset between AlInP and TiO2 blocks interfacial hole transport, resulting in a small overall reverse saturation current, improving the photovoltage. This feature is important for achieving high STH efficiencies.
The influence of the surface modifications on optical properties and on the photocurrent is shown in Figure 2. A reduction of the reflectivity by ∼15% is achieved by use of the TiO2 interlayer (Supporting Information section S5), whereas the Rh NPs in Figure 2a show negligible additional absorption, which is attributed to the blue-shifted plasmonic resonance of the Rh NPs. For particle sizes below 20 nm, a shift from the visible region into the ultraviolet one occurs, making the Rh layer almost fully transparent.(14−16) The detailed optimization of the optical design regarding the thickness of TiO2 and Rh particle size is discussed in Supporting Information section S6 including both simulations and experimental support.
Figure 2
Figure 2. Optoelectronic properties of the surface-functionalized electrolyte/Rh/TiO2/oxide/AlInP–GaInP/GaInAs/GaAs water splitting device; (a) reflectivity Ra, measured in air, of the dual-junction tandem solar cell without ARC (black curve) and second reflectivity obtained after TiO2 coating (blue curve) and after photoelectrochemically deposited Rh NPs (yellow curve); Ra is larger than that under operation in electrolyte due to the different refractive indices of air and water; (b) comparison of the output characteristics of the tandem device after cap layer etching and of the full surface-functionalized photoelectrode. The orange arrows indicate the improvement after incorporation of the TiO2 layer.
The corresponding photocurrent–voltage characteristics in acidic electrolyte demonstrate a pronounced increase in the current and, as expected, also a shift of the bend of the photocurrent characteristic toward more anodic potentials, thereby additionally increasing the photocurrent at the RuO2 counter electrode (OER) potential. The result with incorporation of TiO2 is a relative increase of 28% of the tandem cell output. A STH efficiency of 19.3% is obtained at 0 V, with an operating current of 15.7 mA/cm2, assuming an initial Faradaic efficiency of unity, which is supported by the gas evolution measurements shown in Figure 3b. These data represent a 20% increase in efficiency above the previously reported 1 sun photoelectrosynthetic cell efficiency benchmark.(6)
Figure 3
Figure 3. Output characteristics of the RuO2–GaAs/GaInAs/GaInP/AlInP–anatase TiO2–Rh/electrolyte dual-junction tandem structure: (a) photocurrent–voltage characteristics in acidic (pH 0) and neutral (pH 7) electrolyte and in neutral electrolyte including an AEM membrane; (b) chronoamperometric data of the initial temporal regime; (c) stability measurements at −0.4 V vs a RuO2 counter electrode for acidic and neutral pH; (d) hydrogen and oxygen gas collection for operation in acidic (open spheres) and neutral (full spheres) electrolyte. The measured gas volume for oxygen (blue symbols) and hydrogen (red symbols) is overlaid with the expected produced gas volume, as calculated from charge passed through the anode and cathode.
The high photocurrent at 0 V vs RuO2 indicates that electron transport is virtually uninhibited from the absorber layer through the indium and phosphorus oxide and TiO2 interfacial layers to the electrolyte. The corresponding energy band relations can be inferred from surface characterization using ultraviolet and X-ray photoelectron spectroscopy. While the simplest approach to assessment of band alignment follows Anderson’s idealized model(17) for planar contacts and does not consider energy band shifts due to surface and/or interface dipoles, this approach certainly does not apply here as the junctions formed at the AlInP/oxide, oxide/TiO2, and TiO2/Rh/electrolyte interfaces are complex. Thus, the energy band diagram of the heterojunction structure was inferred from ultraviolet and X-ray photoelectron spectroscopy measurements and can be found in the Supporting Information section S4. It should be noted that equilibrium formation between small metallic catalyst NPs and semiconductors appears to depend on the substrate doping level(5) and obviously does not follow a Schottky thermionic emission model, in particular, in contact with an electrolyte.(18,19) In addition, metal work functions depend on NP size;(20) therefore, comparison of the energy levels of NP catalyst layers with planar thin films is notably challenging; therefore, only an estimate of the NP catalyst layer energy level can be given, supported by the device operating data.
The output data shown in Figure 2b were obtained in an acidic electrolyte of pH 0. Figure 3 summarizes the main performance characteristics. Figure 3a illustrates the photocurrent–voltage characteristics under three conditions: (i) at pH 0 with 19.3% STH, (ii) at neutral pH with 18.5% STH, and (iii) using an anion exchange membrane (AEM) with a STH of 14.8%. The observed unassisted water splitting efficiencies critically depend on the experimental conditions (details about the efficiency benchmarking of our PEC device under AM 1.5G conditions, as well as a discussion of efficiency accuracy and polarization loss, are given in the Supporting Information section S7).
Figure 3b gives the unassisted two-electrode photocurrent density vs time for the initial operation regime, showing that while the photocurrent density decreases with time for acidic pH it remains more stable in neutral pH solutions. Chronoamperometric tests (at −0.4 V vs counter electrode, as shown in Figure 3c) show that the device photocurrent density decreases in an acidic electrolyte to low values within 3 h. However, in neutral pH electrolyte, stability over 20 h was demonstrated, with the photocurrent density remaining at 83% of its initial value (see comparative PEC test conditions and results in the Supporting Information section S8). In both cases, for pH 0 and 7, near-unity Faradaic efficiency is confirmed through the agreement between the expected (solid line) and measured gas volumes (symbols) in Figure 3d. However, whereas the curves for pH 7 stay linear with a constant gas production rate for H2/O2, as expected from the stability measurements, the curves for pH 0 show a deviation from linearity due to the decreasing photocurrent.
Etching of TiO2 is expected to occur at pH 0 but not at pH 7, as can be seen in the TiO2 Pourbaix diagram in Supporting Informatoin section S10. Corrosion reactions can degrade the junction photovoltage, as well as lead to undercutting and removal of catalyst particles, thus reducing the exchange current of the Rh NP arrangement and slowing of the HER kinetics. The system reacts also sensitively to series resistance changes, as illustrated by characteristics for devices employing an anion exchange membrane. The bend of the J–V curve is shifted to cathodic potentials. However, device operation at pH 7 still yields a high STH efficiency of 18.5% and the device appears to be stable for a more extended period, in accordance with predictions of TiO2 stability from thermodynamics. Even a slower reduction of the photocurrent is observed; we found that this photocurrent reduction could be partially reversed by immersion of the device from the electrolyte solution and applying a soft cleansing procedure (see Supporting Information section S8). The observation that the photocurrent can be partially restored appears to rule out loss of Rh catalyst particles or even partial removal of the anatase interfacial layer as causes of photocurrent reduction. We find, however, that the surface chemistry of Rh is influenced by the phosphate buffer of the neutral electrolyte; XPS in Supporting Information section S10 clearly indicates PO4 formation on the Rh surfaces because of the absence of an In signal, which would have been observed in case of InPOx formation, concurrent with corrosion of the absorber. The photoelectrode regeneration procedure results in a 50% recovery of the photocurrent lost during the first 12 h, suggesting that the high porosity of the Rh NP layer inhibits full recovery by short intermediate treatment. Employing a different electrolyte for pH 7 conditions might therefore benefit long-term activity of the device. (see details in Supporting Information section S10).
Increasing the efficiency of a photoelectrosynthetic device from already high values toward theoretical limits is especially challenging. We have used a series of surface conditioning steps that have a two-fold function: light management was drastically improved and the electronic properties were at least maintained. Compared to our earlier results,(5) we see an increase in the available cell voltage that is related to the increase in photocurrent at the counter electrode operation potential. Junction formation between the etched AlInP layer, TiO2 layer, and Rh NPs suggests that the Fermi level alignment is nearly ideal.
Figure 4 shows a summary to date of selected STH efficiencies realized for monolithic integrated photoelectrosynthetic devices capable of unassisted water splitting.
Figure 4
Figure 4. Comparison of realized limiting STH efficiencies and historic development. The analysis refers to a theoretical benchmarking value ηtheo (see text) and takes into account the top and bottom cell band gaps for the respective photolysis cells; also shown are the institutions of the contributing research teams. Abbreviations: NREL - National Renewable Energy Laboratory, USA; ISE - Institute for Solar Energy, Germany; JCAP - Joint Center for Artificial Photosynthesis, Caltech; TU-I - Ilmenau University of Technology, Germany; HZB - Helmholtz Zentrum Berlin, Germany. The bar chart on the right indicates the achieved efficiency with respect to the respective theoretical limit (ηtheo*). See detail values in Supporting Information section S10.
Using the parameters shown in Table 1, our photoelectrosynthetic device reaches 0.85 of the theoretical limiting efficiency. It should be noted that the theoretical efficiency determined from the data in Table 1 is based on the best presently known electrocatalysts, a unity photoelectrode radiative efficiency, and an absence of absorption losses.(9) We also calculated the STH efficiency as a function of Tafel slope, exchange current density, and ohmic drop to evaluate whether the optical or the electrochemical polarization losses dominate the solar cell performance (see Supporting Information section S7, Figure S17). Our record device is located in the region of highest efficiency, showing that the optical loss is the limiting factor. However, the system, in principle, reacts sensitively to the polarization losses, emphasizing the importance of judiciously combining the interface and catalyst.
| J0,cathode [mA cm–2] | J0, anode [mA cm–2] | fabs | ERE | Rs [Ω] | Rsh [Ω] | |
|---|---|---|---|---|---|---|
| ideal | ∞ | ∞ | 1 | 1 | 0 | ∞ |
| JXC limited | 1 | 10–3 | 1 | 1 | 0 | ∞ |
| JXC and optically limited | 1 | 10–3 | 0.9 | 0.03 | 0 | ∞ |
Ideal: only exchange current density-limited and devices that are optically and electrochemically limited are displayed in rows 1–3, respectively. For the used band gap combination and only catalytic exchange current density (JXC) limitation, ηtheo = 22.8% at AM 1.5G irradiation.
Stability appears to remain an issue of this photocathode device configuration, but we have demonstrated high efficiency in neutral electrolytes and that extended operation of photocathode devices becomes possible if one can control the Rh surface chemistry. The use of Rh NPs with tailored size and shape distributions enables ultralow absorption. The future design of even more optimized tandem photoelectrodes appears to be possible, enabling solar fuel generation (water splitting as well as CO2 or N2 reduction) efficiencies to be even higher than those reported here, for example, with STH champion device efficiencies of >20% for integrated direct water photolysis being a realistic goal.
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsenergylett.8b00920.
Device fabrication; materials characterization techniques; TiO2 characterization; surface layer band alignment; absorption enhancement by TiO2; optimization of the optical design; assessment of the solar-to-hydrogen efficiency measurement; comparative PEC test conditions and results; surface tension variation between pH 0 and 7; X-ray photoelectron spectra and mechanism development; and STH benchmarks (PDF)
Terms & Conditions
Electronic Supporting Information files are available without a subscription to ACS Web Editions. The American Chemical Society holds a copyright ownership interest in any copyrightable Supporting Information. Files available from the ACS website may be downloaded for personal use only. Users are not otherwise permitted to reproduce, republish, redistribute, or sell any Supporting Information from the ACS website, either in whole or in part, in either machine-readable form or any other form without permission from the American Chemical Society. For permission to reproduce, republish and redistribute this material, requesters must process their own requests via the RightsLink permission system. Information about how to use the RightsLink permission system can be found at http://pubs.acs.org/page/copyright/permissions.html.
Author Information
- Harry A. Atwater - Department of Applied Physics and Material Science, California Institute of Technology, Pasadena, California 91125, United States; Joint Center for Artificial Photosynthesis, California Institute of Technology, Pasadena, California 91125, United States;
http://orcid.org/0000-0001-9435-0201;
Email: [email protected]
T.H., H.J.L, M.M.M., W.H.C., M.H.R. and H.A.A. conceived of the experimental study. W.H.C. and M.H.R. executed the experiments and did the data analysis. J.O., D.L., and F.D. prepared the tandem absorber. W.H.C., M.H.R., H.J.L., and H.A.A. wrote the paper, and all authors commented on the manuscript.
The authors declare no competing financial interest.
Acknowledgments
The authors acknowledge Katherine T. Fountaine for the calculation of theoretical photocurrent efficiencies of 2J PEC devices. This work was supported through the Office of Science of the U.S. Department of Energy (DOE) under Award No. DE SC0004993 to the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub. Research was in part carried out at the Molecular Materials Research Center of the Beckman Institute of the California Institute of Technology. The work on tandem absorbers was funded by the German Federal Ministry of Education and research (BMBF) under Contract Number FKZ 03F0432A (HyCon). M.M.M. acknowledges funding from the fellowship programme of the German National Academy of Sciences Leopoldina, Grant LPDS 2015-09.
References
This article references 20 other publications.
- 1Walter, M. G.; Warren, E. L.; McKone, J. R.; Boettcher, S. W.; Mi, Q.; Santori, E. A.; Lewis, N. S. Solar Water Splitting Cells. Chem. Rev. 2010, 110, 6446– 6473, DOI: 10.1021/cr1002326[ACS Full Text
], [CAS], Google Scholar1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtl2lsbvF&md5=e805b03c6896be7e34d8f64bfe299a87Solar Water Splitting CellsWalter, Michael G.; Warren, Emily L.; McKone, James R.; Boettcher, Shannon W.; Mi, Qixi; Santori, Elizabeth A.; Lewis, Nathan S.Chemical Reviews (Washington, DC, United States) (2010), 110 (11), 6446-6473CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)A review on the efforts to develop an efficient semiconductor-based photoelectrochem. water splitting device in which the only inputs are sunlight and water. The fundamental principles of photoinduced electron-transfer mechanisms at a semiconductor/liq. junction, and optimization of such processes, are summarized. A wide range of both p- and n-type semiconductor photoelectrode materials that have been studied for photoelectrochem. water splitting cells are then described. In addn., heterogeneous electrocatalysts used to facilitate the oxidn. and redn. reactions in electrochem. and in photoelectrochem. water splitting systems are reviewed. Finally, efforts to combine photoanode, photocathode, and photovoltaic-assisted coupled configurations in both single and dual band gap photoelectrolysis cells are examd. in terms of their solar-to-hydrogen efficiency, stability, and expected viability. Strategies to optimize solar-to-chem. energy-conversion efficiencies by optimization of light harvesting structured semiconductors, photoinduced electron transfer and transport, and surface catalysis are also described. - 2Xiang, C.; Weber, A. Z.; Ardo, S.; Berger, A.; Chen, Y.; Coridan, R.; Fountaine, K. T.; Haussener, S.; Hu, S.; Liu, R. Modeling, Simulation, and Implementation of Solar-Driven Water-Splitting Devices. Angew. Chem., Int. Ed. 2016, 55, 12974– 12988, DOI: 10.1002/anie.201510463[Crossref], [PubMed], [CAS], Google Scholar2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28Xht1GjurvP&md5=4f5a99d8d6d5b3e1a84a48daf9e0f7acModeling, Simulation, and Implementation of Solar-Driven Water-Splitting DevicesXiang, Chengxiang; Weber, Adam Z.; Ardo, Shane; Berger, Alan; Chen, YiKai; Coridan, Robert; Fountaine, Katherine T.; Haussener, Sophia; Hu, Shu; Liu, Rui; Lewis, Nathan S.; Modestino, Miguel A.; Shaner, Matthew M.; Singh, Meenesh R.; Stevens, John C.; Sun, Ke; Walczak, KarlAngewandte Chemie, International Edition (2016), 55 (42), 12974-12988CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)A review is presented. An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochem. (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components. The underlying physics and interactions at the cell level is are reviewed and discussed, followed by an overview of the use of the cell model to provide target properties of materials and guide the design of a range of traditional and unique device architectures.
- 3Fujishima, A.; Honda, K. Electrochemical Photolysis of Water at a Semiconductor Electrode. Nature 1972, 238, 37– 38, DOI: 10.1038/238037a0[Crossref], [PubMed], [CAS], Google Scholar3https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE38XltVykurw%253D&md5=71f39843802b5cdb5f7cb0deb7f0c63cElectrochemical photolysis of water at a semiconductor electrodeFujishima, Akira; Honda, KenichiNature (London, United Kingdom) (1972), 238 (5358), 37-8CODEN: NATUAS; ISSN:0028-0836.For electrochem. decompn. of H2O, a p.d. of >1.23 V is necessary between the anode and the cathode. This p.d. is equal to the energy of radiation with wavelength of ∼1000 nm. This energy, in the form of visible light, can be used effectively in an electrochem. system to decomp. H2O. A novel type of electrochem. cell was developed, in which a TiO2 electrode was connected with a Pt-black electrode through an external load. The direction of current revealed that oxidn. occurred at the TiO2 electrode and redn. at the Pt-black electrode. To increase the efficiency of the process, more reducible species, such as dissolved O2 or Fe3+, must be added in the Pt electrode compartment. The use of a p-type semiconductor electrode instead of Pt leads to more effective electrochem. photolysis of H2O.
- 4Khaselev, O.; Turner, J. A. A Monolithic Photovoltaic-Photoelectrochemical Device for Hydrogen Production via Water Splitting. Science 1998, 280, 425– 427, DOI: 10.1126/science.280.5362.425[Crossref], [PubMed], [CAS], Google Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXivVeltro%253D&md5=52b2fa32c45301e05d032c8a711acbd9A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splittingKhaselev, Oscar; Turner, John A.Science (Washington, D. C.) (1998), 280 (5362), 425-427CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Direct water electrolysis was achieved with a novel, integrated, monolithic photoelectrochem.-photovoltaic design. This photoelectrochem. cell, which is voltage biased with an integrated photovoltaic device, splits water directly upon illumination; light is the only energy input. The hydrogen prodn. efficiency of this system, based on the short-circuit current and the lower heating value of hydrogen, is 12.4 percent.
- 5May, M. M.; Lewerenz, H. J.; Lackner, D.; Dimroth, F.; Hannappel, T. Efficient Direct Solar-to-Hydrogen Conversion by in Situ Interface Transformation of a Tandem Structure. Nat. Commun. 2015, 6, 8286, DOI: 10.1038/ncomms9286[Crossref], [PubMed], [CAS], Google Scholar5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsFeis7zM&md5=f212b3a28f4739c128181f8fc3287b7dEfficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structureMay, Matthias M.; Lewerenz, Hans-Joachim; Lackner, David; Dimroth, Frank; Hannappel, ThomasNature Communications (2015), 6 (), 8286CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)Photosynthesis is nature's route to convert intermittent solar irradn. into storable energy, while its use for an industrial energy supply is impaired by low efficiency. Artificial photosynthesis provides a promising alternative for efficient robust carbon-neutral renewable energy generation. The approach of direct hydrogen generation by photoelectrochem. water splitting utilizes customized tandem absorber structures to mimic the Z-scheme of natural photosynthesis. Here a combined chem. surface transformation of a tandem structure and catalyst deposition at ambient temp. yields photocurrents approaching the theor. limit of the absorber and results in a solar-to-hydrogen efficiency of 14%. The potentiostatically assisted photoelectrode efficiency is 17%. Present benchmarks for integrated systems are clearly exceeded. Details of the in situ interface transformation, the electronic improvement and chem. passivation are presented. The surface functionalization procedure is widely applicable and can be precisely controlled, allowing further developments of high-efficiency robust hydrogen generators.
- 6Young, J. L.; Steiner, M. A.; Döscher, H.; France, R. M.; Turner, J. A.; Deutsch, T. G. Direct Solar-to-Hydrogen Conversion via Inverted Metamorphic Multi-Junction Semiconductor Architectures. Nature Energy 2017, 2, 17028, DOI: 10.1038/nenergy.2017.28[Crossref], [CAS], Google Scholar6https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXot1ykuro%253D&md5=04ac8805e7de2455968709947216ebbcDirect solar-to-hydrogen conversion via inverted metamorphic multi-junction semiconductor architecturesYoung, James L.; Steiner, Myles A.; Doscher, Henning; France, Ryan M.; Turner, John A.; Deutsch, Todd G.Nature Energy (2017), 2 (4), 17028CODEN: NEANFD; ISSN:2058-7546. (Nature Publishing Group)Solar water splitting via multi-junction semiconductor photoelectrochem. cells provides direct conversion of solar energy to stored chem. energy as hydrogen bonds. Economical hydrogen prodn. demands high conversion efficiency to reduce balance-of-systems costs. For sufficient photovoltage, water-splitting efficiency is proportional to the device photocurrent, which can be tuned by judicious selection and integration of optimal semiconductor bandgaps. Here, we demonstrate highly efficient, immersed water-splitting electrodes enabled by inverted metamorphic epitaxy and a transparent graded buffer that allows the bandgap of each junction to be independently varied. Voltage losses at the electrolyte interface are reduced by 0.55 V over traditional, uniformly p-doped photocathodes by using a buried p-n junction. Advanced on-sun benchmarking, spectrally cor. and validated with incident photon-to-current efficiency, yields over 16% solar-to-hydrogen efficiency with GaInP/GaInAs tandem absorbers, representing a 60% improvement over the classical, high-efficiency tandem III-V device.
- 7Lichterman, M. F.; Sun, K.; Hu, S.; Zhou, X.; McDowell, M. T.; Shaner, M. R.; Richter, M. H.; Crumlin, E. J.; Carim, A. I.; Saadi, F. H. Protection of Inorganic Semiconductors for Sustained, Efficient Photoelectrochemical Water Oxidation. Catal. Today 2016, 262, 11– 23, DOI: 10.1016/j.cattod.2015.08.017[Crossref], [CAS], Google Scholar7https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsVCnu77L&md5=9a11b7d506e8d68dd30bcc3f6907d7deProtection of inorganic semiconductors for sustained, efficient photoelectrochemical water oxidationLichterman, Michael F.; Sun, Ke; Hu, Shu; Zhou, Xinghao; McDowell, Matthew T.; Shaner, Matthew R.; Richter, Matthias H.; Crumlin, Ethan J.; Carim, Azhar I.; Saadi, Fadl H.; Brunschwig, Bruce S.; Lewis, Nathan S.Catalysis Today (2016), 262 (), 11-23CODEN: CATTEA; ISSN:0920-5861. (Elsevier B.V.)A review is presented. Small-band-gap (Eg < 2 eV) semiconductors must be stabilized for use in integrated devices that convert solar energy into the bonding energy of a reduced fuel, specifically H2(g) or a reduced-carbon species such as CH3OH or CH4. To sustainably and scalably complete the fuel cycle, electrons must be liberated through the oxidn. of water to O2(g). Strongly acidic or strongly alk. electrolytes are needed to enable efficient and intrinsically safe operation of a full solar-driven water-splitting system. However, under water-oxidn. conditions, the small-band-gap semiconductors required for efficient cell operation are unstable, either dissolving or forming insulating surface oxides. We describe herein recent progress in the protection of semiconductor photoanodes under such operational conditions. We specifically describe the properties of two protective overlayers, TiO2/Ni and NiOx, both of which have demonstrated the ability to protect otherwise unstable semiconductors for >100 h of continuous solar-driven water oxidn. when in contact with a highly alk. aq. electrolyte (1.0 M KOH(aq)). The stabilization of various semiconductor photoanodes is reviewed in the context of the electronic characteristics and a mechanistic anal. of the TiO2 films, along with a discussion of the optical, catalytic, and electronic nature of NiOx films for stabilization of semiconductor photoanodes for water oxidn.
- 8Bae, D.; Pedersen, T.; Seger, B.; Iandolo, B.; Hansen, O.; Vesborg, P. C. K.; Chorkendorff, I. Carrier-Selective P- and N-Contacts for Efficient and Stable Photocatalytic Water Reduction. Catal. Today 2017, 290, 59– 64, DOI: 10.1016/j.cattod.2016.11.028[Crossref], [CAS], Google Scholar8https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhvVygurvL&md5=75480386fbec912085b70707d04b1cb2Carrier-selective p- and n-contacts for efficient and stable photocatalytic water reductionBae, Dowon; Pedersen, Thomas; Seger, Brian; Iandolo, Beniamino; Hansen, Ole; Vesborg, Peter C. K.; Chorkendorff, IbCatalysis Today (2017), 290 (), 59-64CODEN: CATTEA; ISSN:0920-5861. (Elsevier B.V.)The successful realization of carrier-selective contacts for cryst. silicon (c-Si) based device for photocatalytic hydrogen prodn. has been demonstrated. The proposed TiO2 protected carrier-selective contacts resemble a metal-oxide-semiconductor configuration, including a highly-doped nanocryst. silicon (nc-Si) and a tunnel oxide, thereby form a heterostructure with the c-Si substrate. By substituting conventional pn+-junction Si by c-Si/SiOX/nc-Si structure for both front and back contacts we demonstrate a 16% increase in photovoltage (an open circuit voltage of 584 mV under AM 1.5G conditions). TiO2 protected carrier-selective photoelectrodes showed excellent long-term durability in acidic aq. soln. having stable photocurrent output for more than 40 days, implying that the proposed carrier-selective contact is a promising configuration to substitute for the conventional pn-junction based c-Si photocathodes.
- 9Fountaine, K. T.; Lewerenz, H. J.; Atwater, H. A. Efficiency Limits for Photoelectrochemical Water-Splitting. Nat. Commun. 2016, 7, 13706, DOI: 10.1038/ncomms13706[Crossref], [PubMed], [CAS], Google Scholar9https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XitFWns7%252FE&md5=1e8a310493abece8ebf3f925de3e6d3eEfficiency limits for photoelectrochemical water-splittingFountaine, Katherine T.; Lewerenz, Hans Joachim; Atwater, Harry A.Nature Communications (2016), 7 (), 13706CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)Theor. limiting efficiencies have a crit. role in detg. technol. viability and expectations for device prototypes, as evidenced by the photovoltaics community's focus on detailed balance. However, due to their multicomponent nature, photoelectrochem. devices do not have an equiv. analog to detailed balance, and reported theor. efficiency limits vary depending on the assumptions made. Here we introduce a unified framework for photoelectrochem. device performance through which all previous limiting efficiencies can be understood and contextualized. Ideal and exptl. realistic limiting efficiencies are presented, and then generalized using five representative parameters-semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance and catalytic exchange c.d.-to account for imperfect light absorption, charge transport and catalysis. Finally, we discuss the origin of deviations between the limits discussed herein and reported water-splitting efficiencies. This anal. provides insight into the primary factors that det. device performance and a powerful handle to improve device efficiency.
- 10May, M. M.; Lackner, D.; Ohlmann, J.; Dimroth, F.; van de Krol, R.; Hannappel, T.; Schwarzburg, K. On the Benchmarking of Multi-Junction Photoelectrochemical Fuel Generating Devices. Sustainable Energy Fuels 2017, 1, 492– 503, DOI: 10.1039/C6SE00083E[Crossref], [CAS], Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhs1Crs7vI&md5=7482968770ccc922edea71a64b97e89aOn the benchmarking of multi-junction photoelectrochemical fuel generating devicesMay, Matthias M.; Lackner, David; Ohlmann, Jens; Dimroth, Frank; van de Krol, Roel; Hannappel, Thomas; Schwarzburg, KlausSustainable Energy & Fuels (2017), 1 (3), 492-503CODEN: SEFUA7; ISSN:2398-4902. (Royal Society of Chemistry)Photoelectrochem. solar fuel generation is evolving steadily towards devices mature for applications, driven by the development of efficient multi-junction devices. The crucial characteristics deciding over feasibility of an application are efficiency and stability. Benchmarking and reporting routines for these characteristics are, however, not yet on a level of standardisation as in the photovoltaic community, mainly due to the intricacies of the photoelectrochem. dimension. We discuss best practice considerations for benchmarking and propose an alternative efficiency definition that includes stability. Furthermore, we analyze the effects of spectral shaping and anti-reflection properties introduced by catalyst nanoparticles and their impact on design criteria for direct solar fuel generation in monolithic devices.
- 11Sathre, R.; Scown, C. D.; Morrow, W. R.; Stevens, J. C.; Sharp, I. D.; Ager, J. W., III; Walczak, K. A.; Houle, F. A.; Greenblatt, J. B. Life-Cycle Net Energy Assessment of Large-Scale Hydrogen Production via Photoelectrochemical Water Splitting. Energy Environ. Sci. 2014, 7, 3264– 3278, DOI: 10.1039/C4EE01019A[Crossref], [CAS], Google Scholar11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVylsrzI&md5=4c31f8dca23355d5c9735bc3c2ee1643Life-cycle net energy assessment of large-scale hydrogen production via photoelectrochemical water splittingSathre, Roger; Scown, Corinne D.; Morrow, William R., III; Stevens, John C.; Sharp, Ian D.; Ager, Joel W., III; Walczak, Karl; Houle, Frances A.; Greenblatt, Jeffery B.Energy & Environmental Science (2014), 7 (10), 3264-3278CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)Here we report a prospective life-cycle net energy assessment of a hypothetical large-scale photoelectrochem. (PEC) hydrogen prodn. facility with energy output equiv. to 1 GW continuous annual av. (1 GW HHV = 610 metric tons of H2 per day). We det. essential mass and energy flows based on fundamental principles, and use heuristic methods to conduct a preliminary engineering design of the facility. We then develop and apply a parametric model describing system-wide energy flows assocd. with the prodn., utilization, and decommissioning of the facility. Based on these flows, we calc. and interpret life-cycle net energy metrics for the facility. We find that under base-case conditions the energy payback time is 8.1 years, the energy return on energy invested (EROEI) is 1.7, and the life-cycle primary energy balance over the 40 years projected service life of the facility is +500 PJ. The most important model parameters affecting the net energy metrics are the solar-to-hydrogen (STH) conversion efficiency and the life span of the PEC cells; parameters assocd. with the balance of systems (BOS), including construction and operation of the liq. and gas handling infrastructure, play a much smaller role.
- 12Dimroth, F.; Beckert, R.; Meusel, M.; Schubert, U.; Bett, A. W. Metamorphic GayIn1-YP/Ga1-XInXAs Tandem Solar Cells for Space and for Terrestrial Concentrator Applications at C > 1000 Suns. Prog. Photovoltaics 2001, 9, 165– 178, DOI: 10.1002/pip.362[Crossref], [CAS], Google Scholar12https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXksVyqsr8%253D&md5=4ac280908456fc7ffa7c2367c6819267Metamorphic GayIn1-yP/Ga1-xInxAs tandem solar cells for space and for terrestrial concentrator applications at C>1000 sunsDimroth, F.; Beckert, R.; Meusel, M.; Schubert, U.; Bett, A. W.Progress in Photovoltaics (2001), 9 (3), 165-178CODEN: PPHOED; ISSN:1062-7995. (John Wiley & Sons Ltd.)The use of Ga1-xInxAs instead of GaAs as a bottom solar cell in a GayIn1-yP/Ga1-xInxAs tandem structure increases the flexibility of choosing the optimum band-gap combination of materials for a multijunction solar cell. Higher theor. efficiencies are calcd. and different cell concepts are suggested for space and terrestrial concentrator applications. Various GayIn1-yP/Ga1-xInxAs material combinations have been investigated for the first time and efficiencies up to 24.1% (AM0) and 27.0% (AM1.5 direct) have been reached under one-sun conditions. An efficiency of 30.0-31.3% was measured for a Ga0.35In0.65P/Ga0.83In0.17As tandem concentrator cell with prismatic cover at 300 suns. The top and bottom cell layers of this structure are grown lattice-matched to each other, but a large mismatch is introduced at the interface to the GaAs substrate. This cell structure is well suited for the use in next-generation terrestrial concentrators working at high concn. ratios. For the first time a cell efficiency up to 29-30% has been measured at concn. levels up to 1300 suns. A small prototype concentrator with Fresnel lenses and four tandem solar cells working at C=120 has been constructed, with an outdoor efficiency of 23%.
- 13Ohlmann, J.; Sanchez, J. F. M.; Lackner, D.; Förster, P.; Steiner, M.; Fallisch, A.; Dimroth, F. Recent Development in Direct Generation of Hydrogen Using Multi-Junction Solar Cells. AIP Conf. Proc. 2016, 1766, 080004, DOI: 10.1063/1.4962102[Crossref], [CAS], Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsVyqurvO&md5=a9060220eb1d4a62e4309ce94f70cf29Recent development in direct generation of hydrogen using multi-junction solar cellsOhlmann, Jens; Sanchez, Juan Francisco Martinez; Lackner, David; Foerster, Paul; Steiner, Marc; Fallisch, Arne; Dimroth, FrankAIP Conference Proceedings (2016), 1766 (1, 12th International Conference on Concentrator Photovoltaic Systems, 2016), 080004/1-080004/6CODEN: APCPCS; ISSN:0094-243X. (American Institute of Physics)Hydrogen produced from solar energy has a high potential as a storage medium to buffer the fluctuations of renewable energy sources. The direct combination of concentrator photovoltaics with an electrolyzer has the capability to produce Hydrogen from sunlight at high efficiency. For this, the individual components have to be adjusted carefully and optimized with the final system in mind. This paper focuses on the solar cell development and shows first results of the combined module of a solar cell and an electrolyzer. The solar cell used for hydrogen prodn. is a metamorphic GaInP/GaInAs dual-junction solar cell. This tandem cell reaches a max. efficiency of 34.2% under concn. The performance of the combined module shows a strong influence of temp. and DNI. (c) 2016 American Institute of Physics.
- 14Porter, J. D.; Heller, A.; Aspnes, D. E. Experiment and Theory of “Transparent” Metal Films. Nature 1985, 313, 664– 666, DOI: 10.1038/313664a0[Crossref], [CAS], Google Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2MXhsVWls7w%253D&md5=c2973e6ccfa8b25ab8b0987dddead80fExperiment and theory of 'transparent' metal filmsPorter, John D.; Heller, Adam; Aspnes, David E.Nature (London, United Kingdom) (1985), 313 (6004), 664-6CODEN: NATUAS; ISSN:0028-0836.Previous evidence (H., 1984) that Pt layers on p-InP are effectively transparent to incident light or even promote the coupling of incident radiation into the bulk of the semiconductor is explained in terms of microstructure: when the metal films are sufficiently porous and built up from particles smaller than the wavelength of the transmitted light, the photon fields are screened out of the metal phase and are forced into the void structure. This increases the effective refractive index of the layer over that of the ambient and provides a better match with the substrate, while incurring negligible absorption loss.
- 15Degani, Y.; Sheng, T. T.; Heller, A.; Aspnes, D. E.; Studna, A. A.; Porter, J. D. Transparent” Metals: Preparation and Characterization of Light-Transmitting Palladium, Rhodium, and Rhenium Films. J. Electroanal. Chem. Interfacial Electrochem. 1987, 228, 167– 178, DOI: 10.1016/0022-0728(87)80105-5[Crossref], [CAS], Google Scholar15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2sXlvVGqsbo%253D&md5=10821839548581e77265d65201c82774"Transparent" metals: preparation and characterization of light-transmitting palladium, rhodium, and rhenium filmsDegani, Y.; Sheng, T. T.; Heller, A.; Aspnes, D. E.; Studna, A. A.; Porter, J. D.Journal of Electroanalytical Chemistry and Interfacial Electrochemistry (1987), 228 (1-2), 167-78CODEN: JEIEBC; ISSN:0022-0728.The principles that govern the prepn. and properties of transparent Pt films apply also to films of Pd, Rh and Re. Films of these metals, of 42-60 nm thickness, having a metal vol. fraction between 0.3 and 0.5, transmit more light than equiv., dense metal films of identical metal loadings per unit area. The films are prepd. by photoelectrodeposition onto p-InP (100) photocathodes, from ∼5 × 10-5 M solns. of the metal ions in 1M HClO4, under mass-transport limited conditions, at deposition rates of ∼2 nm/h. The transparent Rh, Re and Pd films exhibit their normal catalytic behavior and have normal crystal structures. While the transparent Rh and Pd films, like the bulk metals, are stable in air, the Re films oxidize over a period of days to form films that are either truly amorphous or consist of crystallites of <1 nm diam. The spectroellipsometrically measured dielec. functions of these films in air are analyzed, in the framework of the Bruggeman effective medium approxn., to yield film thicknesses, metal vol. fractions, and mean depolarization factors. The resp. depolarization factors of Rh, Pd, and Re indicate dendritic, particulate, and platelet microstructures, consistent with the structures obsd. by TEM. With the spectroellipsometrically derived, substantially divergent, depolarization factors for the different microstructures, one obtains consistent relations among film thicknesses, metal vol. fractions, and the optical properties. Absorption in tenuous films, of const. metal loading but different microstructures, tends to different finite values strongly dependent on microstructure, in the limit of infinite metal diln.
- 16Sanz, J. M.; Ortiz, D.; Alcaraz de la Osa, R.; Saiz, J. M.; González, F.; Brown, A. S.; Losurdo, M.; Everitt, H. O.; Moreno, F. UV Plasmonic Behavior of Various Metal Nanoparticles in the Near- and Far-Field Regimes: Geometry and Substrate Effects. J. Phys. Chem. C 2013, 117, 19606– 19615, DOI: 10.1021/jp405773p[ACS Full Text], [CAS], Google Scholar16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht12hu7nO&md5=01a1a877dde7db4be5161255688fba15UV Plasmonic Behavior of Various Metal Nanoparticles in the Near- and Far-Field Regimes: Geometry and Substrate EffectsSanz, J. M.; Ortiz, D.; Alcaraz de la Osa, R.; Saiz, J. M.; Gonzalez, F.; Brown, A. S.; Losurdo, M.; Everitt, H. O.; Moreno, F.Journal of Physical Chemistry C (2013), 117 (38), 19606-19615CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)The practical efficacy of technol. promising metals for use in UV plasmonics (3-6 eV) is assessed by an exhaustive numerical anal. This begins with ests. of the near- and far-field electromagnetic enhancement factors of isolated hemispherical and spherical metallic nanoparticles deposited on typical dielec. substrates like Al2O3, from which the potential of each metal for plasmonic applications may be ascertained. The UV plasmonic behavior of Al, Cr, Cu, Ga, In, Mg, Pd, Pt, Rh, Ru, Ti, and W was compared with the known behavior of Au and Ag in the visible. After exploring this behavior for each metal as a function of nanoparticle shape and size, the deleterious effect caused by the metal's native oxide is considered, and the potential for applications such as surface-enhanced Raman spectroscopy, accelerated photodegrdn. and photocatalysis is addressed.
- 17Anderson, R. L. Germanium-Gallium Arsenide Heterojunctions. IBM J. Res. Dev. 1960, 4, 283– 287, DOI: 10.1147/rd.43.0283[Crossref], [CAS], Google Scholar17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaF3MXhtF2jug%253D%253D&md5=b0e27dfee4f598aceb0f3b8a94780225Germanium-gallium arsenide heterojunctionsAnderson, R. L.(1960), 4 (), 283-7 ISSN:.The method of M. (cf. preceding abstr.) was used to prep. abrupt monocryst. junctions between 2 different semiconductor materials by depositing Ge epitaxially on Ga-As substrates. The junctions produced exhibited rectification properties. Tunnel junctions were also made. Tentative results of a study of the elec. characteristics of these junctions are presented.
- 18Skorupska, K.; Pettenkofer, C.; Sadewasser, S.; Streicher, F.; Haiss, W.; Lewerenz, H. J. Electronic and Morphological Properties of the Electrochemically Prepared Step Bunched Silicon (111) Surface. Phys. Status Solidi B 2011, 248, 361– 369, DOI: 10.1002/pssb.201046454[Crossref], [CAS], Google Scholar18https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtVWqu7s%253D&md5=5db6131b6578e958ce0ddf7d20cdedbbElectronic and morphological properties of the electrochemically prepared step bunched silicon (1 1 1) surfaceSkorupska, K.; Pettenkofer, Ch.; Sadewasser, S.; Streicher, F.; Haiss, W.; Lewerenz, H. J.Physica Status Solidi B: Basic Solid State Physics (2011), 248 (2), 361-369CODEN: PSSBBD; ISSN:0370-1972. (Wiley-VCH Verlag GmbH & Co. KGaA)Topog. and electronic and properties of step bunched Si(1 1 1), prepd. by electrochem. processing in alk. soln., are analyzed. Tapping mode at. force microscopy (TM AFM) anal. shows that one bunched step consists of about 15 at. steps (each 0.314 nm in height) and that the (111) oriented terraces have widths that range from 150 to 250 nm. Scanning tunneling microscopy (STM) expts. show a corrugation of the (1 1 1) terraces with an rms roughness of 0.5-0.8 nm, correlated with etch pits in alk. soln. LEED data show a splitting of the (10) and (01) spot from which a min. terrace width of 4.8 nm have been calcd. in good agreement with the TM AFM data. Kelvin probe force microscopy (KPFM) expts. show a decrease of the contact p.d. (CPD) at and near the edges of steps indicating a more neg. charged surface area. Synchrotron radiation photoelectron spectroscopy (SRPES) on electrochem. and purely chem. prepd. step bunched surfaces is compared. From the Si 2p core level shift, and, in particular, from the onset of the valence band emission, an accumulation layer-type shift is obsd. on the electrochem. prepd. sample that is absent for chem. prepn. The move of the Fermi level toward the conduction band min. of the electrochem. conditioned samples is interpreted by H incorporation and discussed by a doping model that involves the mechanism of hydrogen evolution.
- 19Rizk, R.; de Mierry, P.; Ballutaud, D.; Aucouturier, M.; Mathiot, D. Hydrogen Diffusion and Passivation Processes in P- And N-Type Crystalline Silicon. Phys. Rev. B: Condens. Matter Mater. Phys. 1991, 44, 6141– 6151, DOI: 10.1103/PhysRevB.44.6141[Crossref], [PubMed], [CAS], Google Scholar19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3MXmt1Sisro%253D&md5=502e3248d7584091f5466cdba455882bHydrogen diffusion and passivation processes in p- and n-type crystalline siliconRizk, R.; De Mierry, P.; Ballutaud, D.; Aucouturier, M.; Mathiot, D.Physical Review B: Condensed Matter and Materials Physics (1991), 44 (12), 6141-51CODEN: PRBMDO; ISSN:0163-1829.Several deuteration expts. on cryst. silicon have been performed for various shallow dopant impurities (B and Al for p-type silicon; P and As for n-type silicon) and for different temps. and times of plasma exposure. Deuterium diffusion depth profiles obtained by SIMS were simulated with an improved version of a previously reported model. A careful anal. of the SIMS data has allowed the redn. of the no. of fit parameters, by excluding the H2 mol. formation and by a rough est. of the neutral-deuterium diffusion coeff. and of the surface concn. of neutral deuterium. The diffusion coeffs. and related activation energies of the hydrogen species H0, H-, and H+ were detd., leading to a stated ranking of the mobilities in the order H0 < H- < H+. The dissocn. energies of BH, AlH, and PH complexes were also calcd. and have allowed the authors to deduce the corresponding bonding energies of the complexes, which suggest a scaling of the complex stability in the order PH < BH < AlH. Free-carrier depth profiles obtained by high-frequency capacitance-voltage measurements, combined with chem. etching, provided direct evidence of the rate of passivation of the shallow p-type-dopant impurities. The comparison between both couples of depth profiles (deuterium diffusion and carrier concns.), in the case of p-type silicon, showed good agreement between the deactivation process of dopants and the corresponding depth penetration of deuterium.
- 20Zhang, Y.; Pluchery, O.; Caillard, L.; Lamic-Humblot, A.-F.; Casale, S.; Chabal, Y. J.; Salmeron, M. B. Sensing the Charge State of Single Gold Nanoparticles via Work Function Measurements. Nano Lett. 2015, 15, 51– 55, DOI: 10.1021/nl503782s[ACS Full Text], [CAS], Google Scholar20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVClsL3O&md5=9ee388f8e69328cff05bb27ecd3b5732Sensing the Charge State of Single Gold Nanoparticles via Work Function MeasurementsZhang, Yingjie; Pluchery, Olivier; Caillard, Louis; Lamic-Humblot, Anne-Felicie; Casale, Sandra; Chabal, Yves J.; Salmeron, MiquelNano Letters (2015), 15 (1), 51-55CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)Electrostatic interactions at the nanoscale can lead to novel properties and functionalities that bulk materials and devices do not have. Here the authors used Kelvin probe force microscopy (KPFM) to study the work function (WF) of Au nanoparticles (NPs) deposited on a Si wafer covered by a monolayer of alkyl chains, which provide a tunnel junction. The WF of Au NPs is size-dependent and deviates strongly from that of the bulk Au. The authors attribute the WF change to the charging of the NPs, which is a consequence of the difference in WF between Au and the substrate. For an NP with 10 nm diam. charged with ∼5 electrons, the WF is only ∼3.6 eV. A classical electrostatic model is derived that explains the observations in a quant. way. Also the WF and charge state of Au NPs are influenced by chem. changes of the underlying substrate. Therefore, Au NPs could be used for chem. and biol. sensing, whose environmentally sensitive charge state can be read out by work function measurements.
Cited By
This article is cited by 112 publications.
- Marja Nappa, Michael Lienemann, Camilla Tossi, Peter Blomberg, Jussi Jäntti, Ilkka Juhani Tittonen, Merja Penttilä. Solar-Powered Carbon Fixation for Food and Feed Production Using Microorganisms—A Comparative Techno-Economic Analysis. ACS Omega 2020, Article ASAP.
- Srinivas Vanka, Baowen Zhou, Rasha A. Awni, Zhaoning Song, Faqrul A. Chowdhury, Xuedong Liu, Hamed Hajibabaei, Wen Shi, Yixin Xiao, Ishtiaque A. Navid, Ayush Pandey, Rong Chen, Gianluigi A. Botton, Thomas W. Hamann, Dunwei Wang, Yanfa Yan, Zetian Mi. InGaN/Si Double-Junction Photocathode for Unassisted Solar Water Splitting. ACS Energy Letters 2020, 5
(12)
, 3741-3751. https://doi.org/10.1021/acsenergylett.0c01583
- A. Ziani, I. Al-Shankiti, M. A. Khan, H. Idriss. Integrated Photo-Electrocatalytic (PEC) Systems for Water Splitting to Hydrogen and Oxygen under Concentrated Sunlight: Effect of Internal Parameters on Performance. Energy & Fuels 2020, 34
(10)
, 13179-13185. https://doi.org/10.1021/acs.energyfuels.0c02481
- Subash Rajasekar, Vinay Tiwari, Umish Srivastva, Steven Holdcroft. Effectiveness of CuO Nanoparticle-Based p–n Bulk-Heterojunction Electrodes for Photoelectrochemical Hydrogen Generation. ACS Applied Energy Materials 2020, 3
(9)
, 8988-9001. https://doi.org/10.1021/acsaem.0c01419
- Micha Ben-Naim, Reuben J. Britto, Chase W. Aldridge, Rachel Mow, Myles A. Steiner, Adam C. Nielander, Laurie A. King, Daniel J. Friedman, Todd G. Deutsch, James L. Young, Thomas F. Jaramillo. Addressing the Stability Gap in Photoelectrochemistry: Molybdenum Disulfide Protective Catalysts for Tandem III–V Unassisted Solar Water Splitting. ACS Energy Letters 2020, 5
(8)
, 2631-2640. https://doi.org/10.1021/acsenergylett.0c01132
- Haotian Shi, Ryan T. Pekarek, Ran Chen, Boxin Zhang, Yu Wang, Indu Aravind, Zhi Cai, Lasse Jensen, Nathan R. Neale, Stephen B. Cronin. Monitoring Local Electric Fields using Stark Shifts on Napthyl Nitrile-Functionalized Silicon Photoelectrodes. The Journal of Physical Chemistry C 2020, 124
(31)
, 17000-17005. https://doi.org/10.1021/acs.jpcc.0c03966
- Dibyendu Ghosh, Pooja Devi, Omkar Singh Kushwaha, Rajnish Kumar, Praveen Kumar. In Operando Generation and Storage of Hydrogen by Coupling Monolithically Integrated Photoelectrochemical Cell with Clathrate Hydrates Molecular Storage. ACS Applied Energy Materials 2020, 3
(7)
, 6834-6844. https://doi.org/10.1021/acsaem.0c00945
- Moritz Kölbach, Hannes Hempel, Karsten Harbauer, Markus Schleuning, Andrei Petsiuk, Katja Höflich, Victor Deinhart, Dennis Friedrich, Rainer Eichberger, Fatwa F. Abdi, Roel van de Krol. Grain Boundaries Limit the Charge Carrier Transport in Pulsed Laser Deposited α-SnWO4 Thin Film Photoabsorbers. ACS Applied Energy Materials 2020, 3
(5)
, 4320-4330. https://doi.org/10.1021/acsaem.0c00028
- Behrooz Eftekharinia, Hossein Pezeshki, Ali Dabirian. Unassisted Water Splitting Using Standard Silicon Solar Cells Stabilized with Copper and Bifunctional NiFe Electrocatalysts. ACS Applied Materials & Interfaces 2020, 12
(15)
, 17424-17435. https://doi.org/10.1021/acsami.9b22622
- Yubin Chen, Xiaoyang Feng, Ya Liu, Xiangjiu Guan, Clemens Burda, Liejin Guo. Metal Oxide-Based Tandem Cells for Self-Biased Photoelectrochemical Water Splitting. ACS Energy Letters 2020, 5
(3)
, 844-866. https://doi.org/10.1021/acsenergylett.9b02620
- Wen-Hui Cheng, Matthias H. Richter, Ian Sullivan, David M. Larson, Chengxiang Xiang, Bruce S. Brunschwig, Harry A. Atwater. CO2 Reduction to CO with 19% Efficiency in a Solar-Driven Gas Diffusion Electrode Flow Cell under Outdoor Solar Illumination. ACS Energy Letters 2020, 5
(2)
, 470-476. https://doi.org/10.1021/acsenergylett.9b02576
- Julie Tournet, Yonghwan Lee, Siva K. Karuturi, Hark H. Tan, Chennupati Jagadish. III–V Semiconductor Materials for Solar Hydrogen Production: Status and Prospects. ACS Energy Letters 2020, 5
(2)
, 611-622. https://doi.org/10.1021/acsenergylett.9b02582
- Xueqiang Zhang, Tuan Anh Pham, Tadashi Ogitsu, Brandon C. Wood, Sylwia Ptasinska. Modulation of Surface Bonding Topology: Oxygen Bridges on OH-Terminated InP (001). The Journal of Physical Chemistry C 2020, 124
(5)
, 3196-3203. https://doi.org/10.1021/acs.jpcc.9b11548
- Sisir Yalamanchili, Erik Verlage, Wen-Hui Cheng, Katherine T. Fountaine, Philip R. Jahelka, Paul A. Kempler, Rebecca Saive, Nathan S. Lewis, Harry A. Atwater. High Broadband Light Transmission for Solar Fuels Production Using Dielectric Optical Waveguides in TiO2 Nanocone Arrays. Nano Letters 2020, 20
(1)
, 502-508. https://doi.org/10.1021/acs.nanolett.9b04225
- Paul A. Kempler, Harold J. Fu, Zachary P. Ifkovits, Kimberly M. Papadantonakis, Nathan S. Lewis. Spontaneous Formation of >90% Optically Transmissive, Electrochemically Active CoP Films for Photoelectrochemical Hydrogen Evolution. The Journal of Physical Chemistry Letters 2020, 11
(1)
, 14-20. https://doi.org/10.1021/acs.jpclett.9b02926
- Xueqiang Zhang, Tadashi Ogitsu, Brandon C. Wood, Tuan Anh Pham, Sylwia Ptasinska. Oxidation-Induced Polymerization of InP Surface and Implications for Optoelectronic Applications. The Journal of Physical Chemistry C 2019, 123
(51)
, 30893-30902. https://doi.org/10.1021/acs.jpcc.9b07260
- Byungwoo Kim, Gi Soon Park, Yun Jeong Hwang, Da Hye Won, Woong Kim, Dong Ki Lee, Byoung Koun Min. Cu(In,Ga)(S,Se)2 Photocathodes with a Grown-In CuxS Catalyst for Solar Water Splitting. ACS Energy Letters 2019, 4
(12)
, 2937-2944. https://doi.org/10.1021/acsenergylett.9b01816
- Dilek
K. Dogutan, Daniel G. Nocera. Artificial Photosynthesis at Efficiencies Greatly Exceeding That of Natural Photosynthesis. Accounts of Chemical Research 2019, 52
(11)
, 3143-3148. https://doi.org/10.1021/acs.accounts.9b00380
- M. A. Khan, Purushothaman Varadhan, Vinoth Ramalingam, Hui-Chun Fu, Hicham Idriss, Jr-Hau He. Importance of Oxygen Measurements during Photoelectrochemical Water-Splitting Reactions. ACS Energy Letters 2019, 4
(11)
, 2712-2718. https://doi.org/10.1021/acsenergylett.9b02151
- Georgios Zafeiropoulos, Hannah Johnson, Sachin Kinge, Mauritius C. M. van de Sanden, Mihalis N. Tsampas. Solar Hydrogen Generation from Ambient Humidity Using Functionalized Porous Photoanodes. ACS Applied Materials & Interfaces 2019, 11
(44)
, 41267-41280. https://doi.org/10.1021/acsami.9b12236
- Pramod
Patil Kunturu, Christos Zachariadis, Lukasz Witczak, Minh D. Nguyen, Guus Rijnders, Jurriaan Huskens. Tandem Si Micropillar Array Photocathodes with Conformal Copper Oxide and a Protection Layer by Pulsed Laser Deposition. ACS Applied Materials & Interfaces 2019, 11
(44)
, 41402-41414. https://doi.org/10.1021/acsami.9b14408
- Yongjie Wang, Jonathan Schwartz, Jiseok Gim, Robert Hovden, Zetian Mi. Stable Unassisted Solar Water Splitting on Semiconductor Photocathodes Protected by Multifunctional GaN Nanostructures. ACS Energy Letters 2019, 4
(7)
, 1541-1548. https://doi.org/10.1021/acsenergylett.9b00549
- Kang Wang, Dingwang Huang, Le Yu, Kuang Feng, Lintao Li, Takashi Harada, Shigeru Ikeda, Feng Jiang. Promising GeSe Nanosheet-Based Thin-Film Photocathode for Efficient and Stable Overall Solar Water Splitting. ACS Catalysis 2019, 9
(4)
, 3090-3097. https://doi.org/10.1021/acscatal.9b00035
- Charles
R. Lhermitte, Kevin Sivula. Alternative Oxidation Reactions for Solar-Driven Fuel Production. ACS Catalysis 2019, 9
(3)
, 2007-2017. https://doi.org/10.1021/acscatal.8b04565
- Kristina Wedege, Dowon Bae, Wilson A. Smith, Adélio Mendes, Anders Bentien. Solar Redox Flow Batteries with Organic Redox Couples in Aqueous Electrolytes: A Minireview. The Journal of Physical Chemistry C 2018, 122
(45)
, 25729-25740. https://doi.org/10.1021/acs.jpcc.8b04914
- Song Jin (Senior Editor, ACS Energy Letters). What Else Can Photoelectrochemical Solar Energy Conversion Do Besides Water Splitting and CO2 Reduction?. ACS Energy Letters 2018, 3
(10)
, 2610-2612. https://doi.org/10.1021/acsenergylett.8b01800
- Hiroshi Irie, Masaomi Yoda, Toshihiro Takashima, Junya Osaki. Silver cocatalyst-concentration dependence of overall water splitting performance over silver-inserted solid-state heterojunction photocatalyst composed of zinc rhodium oxide and bismuth vanadium oxide. Applied Catalysis B: Environmental 2021, 284 , 119744. https://doi.org/10.1016/j.apcatb.2020.119744
- Lipin Chen, Mahdi Alqahtani, Christophe Levallois, Antoine Létoublon, Julie Stervinou, Rozenn Piron, Soline Boyer-Richard, Jean-Marc Jancu, Tony Rohel, Rozenn Bernard, Yoan Léger, Nicolas Bertru, Jiang Wu, Ivan P. Parkin, Charles Cornet. Assessment of GaPSb/Si tandem material association properties for photoelectrochemical cells. Solar Energy Materials and Solar Cells 2021, 221 , 110888. https://doi.org/10.1016/j.solmat.2020.110888
- U Banin, N Waiskopf, L Hammarström, G Boschloo, M Freitag, E M J Johansson, J Sá, H Tian, M B Johnston, L M Herz, R L Milot, M G Kanatzidis, W Ke, I Spanopoulos, K L Kohlstedt, G C Schatz, N Lewis, T Meyer, A J Nozik, M C Beard, F Armstrong, C F Megarity, C A Schmuttenmaer, V S Batista, G W Brudvig. Nanotechnology for catalysis and solar energy conversion. Nanotechnology 2021, 32
(4)
, 042003. https://doi.org/10.1088/1361-6528/abbce8
- Linfeng Pan, Yuhang Liu, Liang Yao, Dan Ren, Kevin Sivula, Michael Grätzel, Anders Hagfeldt. Cu2O photocathodes with band-tail states assisted hole transport for standalone solar water splitting. Nature Communications 2020, 11
(1)
https://doi.org/10.1038/s41467-019-13987-5
- Wooseok Yang, Jin Hyun Kim, Oliver S. Hutter, Laurie J. Phillips, Jeiwan Tan, Jaemin Park, Hyungsoo Lee, Jonathan D. Major, Jae Sung Lee, Jooho Moon. Benchmark performance of low-cost Sb2Se3 photocathodes for unassisted solar overall water splitting. Nature Communications 2020, 11
(1)
https://doi.org/10.1038/s41467-020-14704-3
- Hemin Zhang, Dongfeng Li, Woo Jin Byun, Xiuli Wang, Tae Joo Shin, Hu Young Jeong, Hongxian Han, Can Li, Jae Sung Lee. Gradient tantalum-doped hematite homojunction photoanode improves both photocurrents and turn-on voltage for solar water splitting. Nature Communications 2020, 11
(1)
https://doi.org/10.1038/s41467-020-18484-8
- Xin Sun, Devendra Tiwari, David J. Fermin. High Interfacial Hole‐Transfer Efficiency at GaFeO
3
Thin Film Photoanodes. Advanced Energy Materials 2020, 10
(45)
, 2002784. https://doi.org/10.1002/aenm.202002784
- Wu Zhou, Chung-Li Dong, Yiqing Wang, Yu-Cheng Huang, Lingyun He, Han-Wei Chang, Shaohua Shen. Manipulating metal-oxygen local atomic structures in single-junctional p-Si/WO3 photocathodes for efficient solar hydrogen generation. Nano Research 2020, 238 https://doi.org/10.1007/s12274-020-3223-9
- Charline Wolpert, Thomas Emmler, Maria Villa Vidaller, Andreas Elsenberg, Kentaro Shinoda, Mauricio Schieda, Frank Gärtner, Jun Akedo, Thomas Klassen. Aerosol-Deposited BiVO4 Photoelectrodes for Hydrogen Generation. Journal of Thermal Spray Technology 2020, 24 https://doi.org/10.1007/s11666-020-01104-8
- Andrew H. Proppe, Yuguang C. Li, Alán Aspuru-Guzik, Curtis P. Berlinguette, Christopher J. Chang, Richard Cogdell, Abigail G. Doyle, Johannes Flick, Nathaniel M. Gabor, Rienk van Grondelle, Sharon Hammes-Schiffer, Shaffiq A. Jaffer, Shana O. Kelley, Mario Leclerc, Karl Leo, Thomas E. Mallouk, Prineha Narang, Gabriela S. Schlau-Cohen, Gregory D. Scholes, Aleksandra Vojvodic, Vivian Wing-Wah Yam, Jenny Y. Yang, Edward H. Sargent. Bioinspiration in light harvesting and catalysis. Nature Reviews Materials 2020, 5
(11)
, 828-846. https://doi.org/10.1038/s41578-020-0222-0
- Yaping Zhang, Yuyu Bu, Lin Wang, Jin-Ping Ao. Regulation of the Photogenerated Carrier Transfer Process during Photoelectrochemical Water Splitting: A Review. Green Energy & Environment 2020, https://doi.org/10.1016/j.gee.2020.11.007
- Choongman Moon, Brian Seger, Peter Christian Kjærgaard Vesborg, Ole Hansen, Ib Chorkendorff. Wireless Photoelectrochemical Water Splitting Using Triple-Junction Solar Cell Protected by TiO2. Cell Reports Physical Science 2020, , 100261. https://doi.org/10.1016/j.xcrp.2020.100261
- Tobias A. Kistler, Guosong Zeng, James L. Young, Lien‐Chun Weng, Chase Aldridge, Keenan Wyatt, Myles A. Steiner, Oscar Solorzano, Frances A. Houle, Francesca M. Toma, Adam Z. Weber, Todd G. Deutsch, Nemanja Danilovic. Emergent Degradation Phenomena Demonstrated on Resilient, Flexible, and Scalable Integrated Photoelectrochemical Cells. Advanced Energy Materials 2020, 3 , 2002706. https://doi.org/10.1002/aenm.202002706
- Anupma Thakur, Dibyendu Ghosh, Pooja Devi, Ki-Hyun Kim, Praveen Kumar. Current progress and challenges in photoelectrode materials for the production of hydrogen. Chemical Engineering Journal 2020, 397 , 125415. https://doi.org/10.1016/j.cej.2020.125415
- David J. Lawrence, Brianna L. Smith, Cameron D. Collard, Keyton A. Elliott, Kyle L. Fakhoury, Jeffery D. Mangold, Anna N. Soyka. Monolithically-integrated BiVO4/p+-n GaAs1-xPx tandem photoanodes capable of unassisted solar water splitting. International Journal of Hydrogen Energy 2020, https://doi.org/10.1016/j.ijhydene.2020.10.050
- Jing Lin, Wenliang Wang, Guoqiang Li. Modulating Surface/Interface Structure of Emerging InGaN Nanowires for Efficient Photoelectrochemical Water Splitting. Advanced Functional Materials 2020, 8 , 2005677. https://doi.org/10.1002/adfm.202005677
- Hicham Idriss. Hydrogen production from water: past and present. Current Opinion in Chemical Engineering 2020, 29 , 74-82. https://doi.org/10.1016/j.coche.2020.05.009
- Y.H. Kwok, Y. Wang, Y. Zhang, H. Zhang, F. Li, W. Pan, D.Y.C. Leung. Boosting cell performance and fuel utilization efficiency in a solar assisted methanol microfluidic fuel cell. International Journal of Hydrogen Energy 2020, 45
(41)
, 21796-21807. https://doi.org/10.1016/j.ijhydene.2020.05.163
- Maheswari Arunachalam, Young Jun Seo, Seungwon Jeon, Kwang-Soon Ahn, Chung Soo Kim, Soon Hyung Kang. Colloidal metal Ag nanowire as an efficient co-catalyst for enhancing the solar water oxidation of fluorinated BiVO4 photoelectrode. Chemical Engineering Journal 2020, 394 , 125016. https://doi.org/10.1016/j.cej.2020.125016
- Weilai Yu, Harold J. Fu, Thomas Mueller, Bruce S. Brunschwig, Nathan S. Lewis. Atomic force microscopy: Emerging illuminated and
operando
techniques for solar fuel research. The Journal of Chemical Physics 2020, 153
(2)
, 020902. https://doi.org/10.1063/5.0009858
- M. V. Lebedev. Modification of the Atomic and Electronic Structure of III–V Semiconductor Surfaces at Interfaces with Electrolyte Solutions (Review). Semiconductors 2020, 54
(7)
, 699-741. https://doi.org/10.1134/S1063782620070064
- Siva Krishna Karuturi, Heping Shen, Astha Sharma, Fiona J. Beck, Purushothaman Varadhan, The Duong, Parvathala Reddy Narangari, Doudou Zhang, Yimao Wan, Jr‐Hau He, Hark Hoe Tan, Chennupati Jagadish, Kylie Catchpole. Over 17% Efficiency Stand‐Alone Solar Water Splitting Enabled by Perovskite‐Silicon Tandem Absorbers. Advanced Energy Materials 2020, 10
(28)
, 2000772. https://doi.org/10.1002/aenm.202000772
- Fangliang Gao, Qing Liu, Jiang Shi, Shuti Li. Recent Progress in Gallium Nitride for Photoelectrochemical Water Splitting. 2020,,https://doi.org/10.5772/intechopen.92848
- Paul A. Kempler, Robert H. Coridan, Nathan S. Lewis. Effects of bubbles on the electrochemical behavior of hydrogen-evolving Si microwire arrays oriented against gravity. Energy & Environmental Science 2020, 13
(6)
, 1808-1817. https://doi.org/10.1039/D0EE00356E
- Fatwa F. Abdi, Ronald Ramiro Gutierrez Perez, Sophia Haussener. Mitigating voltage losses in photoelectrochemical cell scale-up. Sustainable Energy & Fuels 2020, 4
(6)
, 2734-2740. https://doi.org/10.1039/D0SE00246A
- Carles Ros, Teresa Andreu, Joan R. Morante. Photoelectrochemical water splitting: a road from stable metal oxides to protected thin film solar cells. Journal of Materials Chemistry A 2020, 8
(21)
, 10625-10669. https://doi.org/10.1039/D0TA02755C
- Ningsi Zhang, Xin Wang, Jianyong Feng, Huiting Huang, Yongsheng Guo, Zhaosheng Li, Zhigang Zou. Paving the road toward the use of β-Fe2O3 in solar water splitting: Raman identification, phase transformation and strategies for phase stabilization. National Science Review 2020, 7
(6)
, 1059-1067. https://doi.org/10.1093/nsr/nwaa039
- Jitendra N. Tiwari, Aditya Narayan Singh, Siraj Sultan, Kwang S. Kim. Recent Advancement of p‐ and d‐Block Elements, Single Atoms, and Graphene‐Based Photoelectrochemical Electrodes for Water Splitting. Advanced Energy Materials 2020, 10
(24)
, 2000280. https://doi.org/10.1002/aenm.202000280
- Edmund Samuel, Bhavana Joshi, Min-Woo Kim, Mark T. Swihart, Sam S. Yoon. Morphology engineering of photoelectrodes for efficient photoelectrochemical water splitting. Nano Energy 2020, 72 , 104648. https://doi.org/10.1016/j.nanoen.2020.104648
- Kang Wang, Dingwang Huang, Lintao Li, Kuang Feng, Takashi Harada, Shigeru Ikeda, Jingbo Li, Feng Jiang. Three‐Dimensional GeSe Microstructured Air Brick Photocathode for Advanced Solar Water Splitting. Solar RRL 2020, 4
(5)
, 1900559. https://doi.org/10.1002/solr.201900559
- Jagat Das, Partha Pratim Sahu, Pritam Deb. H2 evolution through solar guided water splitting using Fe based composite electrode. Materials Today: Proceedings 2020, https://doi.org/10.1016/j.matpr.2020.04.877
- M.A. Nadeem, H. Idriss. Effect of pH, temperature, and low light flux on the performance (16% STH) of coupled triple junction solar cell to water electrolysis. Journal of Power Sources 2020, 459 , 228074. https://doi.org/10.1016/j.jpowsour.2020.228074
- Behrooz Eftekharinia, Davood Danaei, Ali Dabirian. Computational study of film morphology impact on light absorption in particulate Ta
3
N
5
/Si photoanodes for water splitting. Journal of Physics D: Applied Physics 2020, 53
(18)
, 185501. https://doi.org/10.1088/1361-6463/ab7512
- Wolfram Jaegermann, Bernhard Kaiser, Friedhelm Finger, Vladimir Smirnov, Rolf Schäfer. Design Considerations of Efficient Photo-Electrosynthetic Cells and its Realization Using Buried Junction Si Thin Film Multi Absorber Cells. Zeitschrift für Physikalische Chemie 2020, 234
(4)
, 549-604. https://doi.org/10.1515/zpch-2019-1584
- Jiangang Jiang, Shichao Zong, Wenyi Ren, He Wang. Crystallite, optical, and photoelectrochemical properties of three-dimensional ZnO/CdS photoelectrodes synthesized by hydrothermal approach. Journal of Photonics for Energy 2020, 10
(02)
, 1. https://doi.org/10.1117/1.JPE.10.023505
- Scott K. Cushing, Ilana J. Porter, Bethany R. de Roulet, Angela Lee, Brett M. Marsh, Szilard Szoke, Mihai E. Vaida, Stephen R. Leone. Layer-resolved ultrafast extreme ultraviolet measurement of hole transport in a Ni-TiO
2
-Si photoanode. Science Advances 2020, 6
(14)
, eaay6650. https://doi.org/10.1126/sciadv.aay6650
- Mark T. Spitler, Miguel A. Modestino, Todd G. Deutsch, Chengxiang X. Xiang, James R. Durrant, Daniel V. Esposito, Sophia Haussener, Stephen Maldonado, Ian D. Sharp, Bruce A. Parkinson, David S. Ginley, Frances A. Houle, Thomas Hannappel, Nathan R. Neale, Daniel G. Nocera, Paul C. McIntyre. Practical challenges in the development of photoelectrochemical solar fuels production. Sustainable Energy & Fuels 2020, 4
(3)
, 985-995. https://doi.org/10.1039/C9SE00869A
- Sitaramanjaneya Mouli Thalluri, Lichen Bai, Cuncai Lv, Zhipeng Huang, Xile Hu, Lifeng Liu. Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting. Advanced Science 2020, 7
(6)
, 1902102. https://doi.org/10.1002/advs.201902102
- Tobias A. Kistler, Peter Agbo. Current loss analysis in photoelectrochemical devices. APL Materials 2020, 8
(3)
, 031107. https://doi.org/10.1063/1.5142561
- Ryan T. Pekarek, Dylan G. Boucher, Nathan R. Neale, Michael J. Rose. Energetic Tug‐of‐War between Pt and Leaky TiO
2
: Positive and Negative Effects on the Function of Molecularly‐Modified
p
‐Si(111)|TiO
2
|Pt Photocathodes. ChemElectroChem 2020, 7
(4)
, 1048-1056. https://doi.org/10.1002/celc.201901758
- Jianyong Feng, Huiting Huang, Shicheng Yan, Wenjun Luo, Tao Yu, Zhaosheng Li, Zhigang Zou. Non-oxide semiconductors for artificial photosynthesis: Progress on photoelectrochemical water splitting and carbon dioxide reduction. Nano Today 2020, 30 , 100830. https://doi.org/10.1016/j.nantod.2019.100830
- O. Romanyuk, I. Gordeev, A. Paszuk, O. Supplie, J.P. Stoeckmann, J. Houdkova, E. Ukraintsev, I. Bartoš, P. Jiříček, T. Hannappel. GaP/Si(001) interface study by XPS in combination with Ar gas cluster ion beam sputtering. Applied Surface Science 2020, , 145903. https://doi.org/10.1016/j.apsusc.2020.145903
- Hicham Idriss. The elusive photocatalytic water splitting reaction using sunlight on suspended nanoparticles: is there a way forward?. Catalysis Science & Technology 2020, 10
(2)
, 304-310. https://doi.org/10.1039/C9CY01818B
- Florence Epron, Daniel Duprez. Hydrogen production by catalytic processes. 2020,,, 57-89. https://doi.org/10.1016/B978-0-12-817110-3.00003-5
- Kuniaki Matoba, Yasuaki Matsuda, Masanari Takahashi, Yoshihisa Sakata, Jinlong Zhang, Shinya Higashimoto. Fabrication of Pt/In2S3/CuInS2 thin film as stable photoelectrode for water splitting under solar light irradiation. Catalysis Today 2020, https://doi.org/10.1016/j.cattod.2020.01.015
- Tobias A. Kistler, Min Young Um, Peter Agbo. Stable Photoelectrochemical Hydrogen Evolution for 1000 h at 14% Efficiency in a Monolithic Vapor-fed Device. Journal of The Electrochemical Society 2020, 167
(6)
, 066502. https://doi.org/10.1149/1945-7111/ab7d93
- Elena Rozzi, Francesco Demetrio Minuto, Andrea Lanzini, Pierluigi Leone. Green Synthetic Fuels: Renewable Routes for the Conversion of Non-Fossil Feedstocks into Gaseous Fuels and Their End Uses. Energies 2020, 13
(2)
, 420. https://doi.org/10.3390/en13020420
- B. R. Jany, A. Janas, W. Piskorz, K. Szajna, A. Kryshtal, G. Cempura, P. Indyka, A. Kruk, A. Czyrska-Filemonowicz, F. Krok. Towards the understanding of the gold interaction with AIII-BV semiconductors at the atomic level. Nanoscale 2020, 3 https://doi.org/10.1039/C9NR10256F
- Vonika Ka-Man Au, Vivian Wing-Wah Yam. . 2020,,https://doi.org/10.1016/B978-0-12-409547-2.14908-X
- Jenny Z. Zhang, Erwin Reisner. Advancing photosystem II photoelectrochemistry for semi-artificial photosynthesis. Nature Reviews Chemistry 2020, 4
(1)
, 6-21. https://doi.org/10.1038/s41570-019-0149-4
- Hongpeng Zhou, Menglei Feng, Kena Song, Bin Liao, Yichang Wang, Ruchuan Liu, Xiangnan Gong, Dingke Zhang, Lingfei Cao, Shijian Chen. A highly [001]-textured Sb
2
Se
3
photocathode for efficient photoelectrochemical water reduction. Nanoscale 2019, 11
(47)
, 22871-22879. https://doi.org/10.1039/C9NR08700A
- Jing Gao, Florent Sahli, Chenjuan Liu, Dan Ren, Xueyi Guo, Jérémie Werner, Quentin Jeangros, Shaik Mohammed Zakeeruddin, Christophe Ballif, Michael Grätzel, Jingshan Luo. Solar Water Splitting with Perovskite/Silicon Tandem Cell and TiC-Supported Pt Nanocluster Electrocatalyst. Joule 2019, 3
(12)
, 2930-2941. https://doi.org/10.1016/j.joule.2019.10.002
- Roland Dittmeyer, Michael Klumpp, Paul Kant, Geoffrey Ozin. Crowd oil not crude oil. Nature Communications 2019, 10
(1)
https://doi.org/10.1038/s41467-019-09685-x
- Mario Borgwardt, Stefan T. Omelchenko, Marco Favaro, Paul Plate, Christian Höhn, Daniel Abou-Ras, Klaus Schwarzburg, Roel van de Krol, Harry A. Atwater, Nathan S. Lewis, Rainer Eichberger, Dennis Friedrich. Femtosecond time-resolved two-photon photoemission studies of ultrafast carrier relaxation in Cu2O photoelectrodes. Nature Communications 2019, 10
(1)
https://doi.org/10.1038/s41467-019-10143-x
- Purushothaman Varadhan, Hui-Chun Fu, Yu-Cheng Kao, Ray-Hua Horng, Jr-Hau He. An efficient and stable photoelectrochemical system with 9% solar-to-hydrogen conversion efficiency via InGaP/GaAs double junction. Nature Communications 2019, 10
(1)
https://doi.org/10.1038/s41467-019-12977-x
- Li Wang, Merranda Schmid, Justin B. Sambur. Single nanoparticle photoelectrochemistry: What is next?. The Journal of Chemical Physics 2019, 151
(18)
, 180901. https://doi.org/10.1063/1.5124710
- Yongjie Wang, Yuanpeng Wu, Jonathan Schwartz, Suk Hyun Sung, Robert Hovden, Zetian Mi. A Single-Junction Cathodic Approach for Stable Unassisted Solar Water Splitting. Joule 2019, 3
(10)
, 2444-2456. https://doi.org/10.1016/j.joule.2019.07.022
- Wooseok Yang, Rajiv Ramanujam Prabhakar, Jeiwan Tan, S. David Tilley, Jooho Moon. Strategies for enhancing the photocurrent, photovoltage, and stability of photoelectrodes for photoelectrochemical water splitting. Chemical Society Reviews 2019, 48
(19)
, 4979-5015. https://doi.org/10.1039/C8CS00997J
- Kwangwook Park, Yeong Jae Kim, Taeho Yoon, Selvaraj David, Young Min Song. A methodological review on material growth and synthesis of solar-driven water splitting photoelectrochemical cells. RSC Advances 2019, 9
(52)
, 30112-30124. https://doi.org/10.1039/C9RA05341G
- Wooseok Yang, Jooho Moon. Rapid advances in antimony triselenide photocathodes for solar hydrogen generation. Journal of Materials Chemistry A 2019, 7
(36)
, 20467-20477. https://doi.org/10.1039/C9TA07990D
- Chu Er Lim, Mei Lee Ooi, Richard C. S. Wong, Kian Eang Neo, Asad Mumtaz, Muhammad Mazhar, Norani Muti Mohamed, Mohamed Shuaib Mohamed Saheed. Facile synthesis of molybdenum multisulfide composite nanorod arrays from single-source precursor for photoelectrochemical hydrogen generation. Applied Nanoscience 2019, 9
(6)
, 1281-1292. https://doi.org/10.1007/s13204-019-00957-y
- Guanyu Liu, Yuan Sheng, Joel W. Ager, Markus Kraft, Rong Xu. Research advances towards large-scale solar hydrogen production from water. EnergyChem 2019, 1
(2)
, 100014. https://doi.org/10.1016/j.enchem.2019.100014
- Friedhelm Finger, Katharina Welter, Félix Urbain, Vladimir Smirnov, Bernhard Kaiser, Wolfram Jaegermann. Photoelectrochemical Water Splitting using Adapted Silicon Based Multi-Junction Solar Cell Structures: Development of Solar Cells and Catalysts, Upscaling of Combined Photovoltaic-Electrochemical Devices and Performance Stability. Zeitschrift für Physikalische Chemie , Article ASAP.
- Sisir Yalamanchili, Paul A. Kempler, Kimberly M. Papadantonakis, Harry A. Atwater, Nathan S. Lewis. Integration of electrocatalysts with silicon microcone arrays for minimization of optical and overpotential losses during sunlight-driven hydrogen evolution. Sustainable Energy & Fuels 2019, 3
(9)
, 2227-2236. https://doi.org/10.1039/C9SE00294D
- Keorock Choi, Kyunghwan Kim, In Kyu Moon, Jangwon Bang, Jungwoo Oh. Subwavelength photocathodes
via
metal-assisted chemical etching of GaAs for solar hydrogen generation. Nanoscale 2019, 11
(32)
, 15367-15373. https://doi.org/10.1039/C9NR03870A
- Luca Mascaretti, Aveek Dutta, Štěpán Kment, Vladimir M. Shalaev, Alexandra Boltasseva, Radek Zbořil, Alberto Naldoni. Plasmon‐Enhanced Photoelectrochemical Water Splitting for Efficient Renewable Energy Storage. Advanced Materials 2019, 31
(31)
, 1805513. https://doi.org/10.1002/adma.201805513
- Yi-Hsuan Chiu, Ting-Hsuan Lai, Ming-Yu Kuo, Ping-Yen Hsieh, Yung-Jung Hsu. Photoelectrochemical cells for solar hydrogen production: Challenges and opportunities. APL Materials 2019, 7
(8)
, 080901. https://doi.org/10.1063/1.5109785
- Thomas Moehl, Wei Cui, René Wick-Joliat, S. David Tilley. Resistance-based analysis of limiting interfaces in multilayer water splitting photocathodes by impedance spectroscopy. Sustainable Energy & Fuels 2019, 3
(8)
, 2067-2075. https://doi.org/10.1039/C9SE00248K
- Alexander N. Bondarchuk, Iván Corrales-Mendoza, Sergio A. Tomás, Frank Marken. A hematite photoelectrode grown on porous and conductive SnO2 ceramics for solar-driven water splitting. International Journal of Hydrogen Energy 2019, 44
(36)
, 19667-19675. https://doi.org/10.1016/j.ijhydene.2019.06.055
- Ashwathi Iyer, Kara Kearney, Elif Ertekin. Computational Approaches to Photoelectrode Design through Molecular Functionalization for Enhanced Photoelectrochemical Water Splitting. ChemSusChem 2019, 12
(9)
, 1858-1871. https://doi.org/10.1002/cssc.201802514
- Jin Hyun Kim, Jae Sung Lee. Elaborately Modified BiVO
4
Photoanodes for Solar Water Splitting. Advanced Materials 2019, 31
(20)
, 1806938. https://doi.org/10.1002/adma.201806938
- Saurabh Tembhurne, Fredy Nandjou, Sophia Haussener. A thermally synergistic photo-electrochemical hydrogen generator operating under concentrated solar irradiation. Nature Energy 2019, 4
(5)
, 399-407. https://doi.org/10.1038/s41560-019-0373-7
- Irwa Issa, Sebastian Delbrück, Ulrich Hamm, . Bioeconomy from experts’ perspectives – Results of a global expert survey. PLOS ONE 2019, 14
(5)
, e0215917. https://doi.org/10.1371/journal.pone.0215917
- Zhibin Luo, Tuo Wang, Jinlong Gong. Single-crystal silicon-based electrodes for unbiased solar water splitting: current status and prospects. Chemical Society Reviews 2019, 48
(7)
, 2158-2181. https://doi.org/10.1039/C8CS00638E
- Jin Hyun Kim, Dharmesh Hansora, Pankaj Sharma, Ji-Wook Jang, Jae Sung Lee. Toward practical solar hydrogen production – an artificial photosynthetic leaf-to-farm challenge. Chemical Society Reviews 2019, 48
(7)
, 1908-1971. https://doi.org/10.1039/C8CS00699G
- Ashwini K. Nangia, Gautam R. Desiraju. Kristall‐Engineering: ein Blick in die Zukunft. Angewandte Chemie 2019, 131
(13)
, 4142-4150. https://doi.org/10.1002/ange.201811313
- Ashwini K. Nangia, Gautam R. Desiraju. Crystal Engineering: An Outlook for the Future. Angewandte Chemie International Edition 2019, 58
(13)
, 4100-4107. https://doi.org/10.1002/anie.201811313
- Paula Perez-Rodriguez, Wouter Vijselaar, Jurriaan Huskens, Machiel Stam, Michael Falkenberg, Miro Zeman, Wilson Smith, Arno H.M. Smets. Designing a hybrid thin-film/wafer silicon triple photovoltaic junction for solar water splitting. Progress in Photovoltaics: Research and Applications 2019, 27
(3)
, 245-254. https://doi.org/10.1002/pip.3085
- Shinjae Hwang, Spencer H. Porter, Anders B. Laursen, Hongbin Yang, Mengjun Li, Viacheslav Manichev, Karin U. D. Calvinho, Voshadhi Amarasinghe, Martha Greenblatt, Eric Garfunkel, G. Charles Dismukes. Creating stable interfaces between reactive materials: titanium nitride protects photoabsorber–catalyst interface in water-splitting photocathodes. Journal of Materials Chemistry A 2019, 7
(5)
, 2400-2411. https://doi.org/10.1039/C8TA12186A
- A. Lenz, O. Supplie, E. Lenz, P. Kleinschmidt, T. Hannappel. Interface of GaP/Si(001) and antiphase boundary facet-type determination. Journal of Applied Physics 2019, 125
(4)
, 045304. https://doi.org/10.1063/1.5080547
- Félix Urbain, Sebastián Murcia-López, Nicole Nembhard, Javier Vázquez-Galván, Cristina Flox, Vladimir Smirnov, Katharina Welter, Teresa Andreu, Friedhelm Finger, Joan Ramón Morante. Solar vanadium redox-flow battery powered by thin-film silicon photovoltaics for efficient photoelectrochemical energy storage. Journal of Physics D: Applied Physics 2019, 52
(4)
, 044001. https://doi.org/10.1088/1361-6463/aaeab9
- S. David Tilley. Recent Advances and Emerging Trends in Photo-Electrochemical Solar Energy Conversion. Advanced Energy Materials 2019, 9
(2)
, 1802877. https://doi.org/10.1002/aenm.201802877
- Shu Hu. Membrane-less photoelectrochemical devices for H
2
O
2
production: efficiency limit and operational constraint. Sustainable Energy & Fuels 2019, 3
(1)
, 101-114. https://doi.org/10.1039/C8SE00329G
- Tobias A. Kistler, Nemanja Danilovic, Peter Agbo. Editors' Choice—A Monolithic Photoelectrochemical Device Evolving Hydrogen in Pure Water. Journal of The Electrochemical Society 2019, 166
(13)
, H656-H661. https://doi.org/10.1149/2.1151913jes
- Matthias M. May, Kira Rehfeld. ESD Ideas: Photoelectrochemical carbon removal as negative emission technology. Earth System Dynamics 2019, 10
(1)
, 1-7. https://doi.org/10.5194/esd-10-1-2019
- Guohua Liu, Jinliang Xu, Kaiying Wang. All-in-one photosynthetic assemblies for solar fuels. Materials Today Energy 2018, 10 , 368-379. https://doi.org/10.1016/j.mtener.2018.10.011
Abstract
Figure 1
Figure 1. Functionalization of a dual-junction tandem as the photoelectrode for unassisted water splitting: (a) schematic of the device structure after functionalization with interfacial films and electrocatalysts (see text); (b) topography of the crystalline anatase TiO2 layer by HRSEM and AFM; (c) protocol of the photoelectrodeposition of Rh NPs; the arrow shows the potential used for stroboscopic deposition under white light illumination, as shown in the upper left inset. The potential choices made are indicated by black dots; the best result was obtained for E = +0.3 V vs SCE. Resulting Rh particles are shown in the inset under the J–V characteristic (upper image: SEM; lower one: AFM). The potential control and corresponding particle size distribution are included in Supporting Information section S1. The root-mean-square surface roughness of TiO2 is 6.3 and 3.6 nm (with/without Rh, respectively).
Figure 2
Figure 2. Optoelectronic properties of the surface-functionalized electrolyte/Rh/TiO2/oxide/AlInP–GaInP/GaInAs/GaAs water splitting device; (a) reflectivity Ra, measured in air, of the dual-junction tandem solar cell without ARC (black curve) and second reflectivity obtained after TiO2 coating (blue curve) and after photoelectrochemically deposited Rh NPs (yellow curve); Ra is larger than that under operation in electrolyte due to the different refractive indices of air and water; (b) comparison of the output characteristics of the tandem device after cap layer etching and of the full surface-functionalized photoelectrode. The orange arrows indicate the improvement after incorporation of the TiO2 layer.
Figure 3
Figure 3. Output characteristics of the RuO2–GaAs/GaInAs/GaInP/AlInP–anatase TiO2–Rh/electrolyte dual-junction tandem structure: (a) photocurrent–voltage characteristics in acidic (pH 0) and neutral (pH 7) electrolyte and in neutral electrolyte including an AEM membrane; (b) chronoamperometric data of the initial temporal regime; (c) stability measurements at −0.4 V vs a RuO2 counter electrode for acidic and neutral pH; (d) hydrogen and oxygen gas collection for operation in acidic (open spheres) and neutral (full spheres) electrolyte. The measured gas volume for oxygen (blue symbols) and hydrogen (red symbols) is overlaid with the expected produced gas volume, as calculated from charge passed through the anode and cathode.
Figure 4
Figure 4. Comparison of realized limiting STH efficiencies and historic development. The analysis refers to a theoretical benchmarking value ηtheo (see text) and takes into account the top and bottom cell band gaps for the respective photolysis cells; also shown are the institutions of the contributing research teams. Abbreviations: NREL - National Renewable Energy Laboratory, USA; ISE - Institute for Solar Energy, Germany; JCAP - Joint Center for Artificial Photosynthesis, Caltech; TU-I - Ilmenau University of Technology, Germany; HZB - Helmholtz Zentrum Berlin, Germany. The bar chart on the right indicates the achieved efficiency with respect to the respective theoretical limit (ηtheo*). See detail values in Supporting Information section S10.
References
ARTICLE SECTIONSThis article references 20 other publications.
- 1Walter, M. G.; Warren, E. L.; McKone, J. R.; Boettcher, S. W.; Mi, Q.; Santori, E. A.; Lewis, N. S. Solar Water Splitting Cells. Chem. Rev. 2010, 110, 6446– 6473, DOI: 10.1021/cr1002326[ACS Full Text], [CAS], Google Scholar1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtl2lsbvF&md5=e805b03c6896be7e34d8f64bfe299a87Solar Water Splitting CellsWalter, Michael G.; Warren, Emily L.; McKone, James R.; Boettcher, Shannon W.; Mi, Qixi; Santori, Elizabeth A.; Lewis, Nathan S.Chemical Reviews (Washington, DC, United States) (2010), 110 (11), 6446-6473CODEN: CHREAY; ISSN:0009-2665. (American Chemical Society)A review on the efforts to develop an efficient semiconductor-based photoelectrochem. water splitting device in which the only inputs are sunlight and water. The fundamental principles of photoinduced electron-transfer mechanisms at a semiconductor/liq. junction, and optimization of such processes, are summarized. A wide range of both p- and n-type semiconductor photoelectrode materials that have been studied for photoelectrochem. water splitting cells are then described. In addn., heterogeneous electrocatalysts used to facilitate the oxidn. and redn. reactions in electrochem. and in photoelectrochem. water splitting systems are reviewed. Finally, efforts to combine photoanode, photocathode, and photovoltaic-assisted coupled configurations in both single and dual band gap photoelectrolysis cells are examd. in terms of their solar-to-hydrogen efficiency, stability, and expected viability. Strategies to optimize solar-to-chem. energy-conversion efficiencies by optimization of light harvesting structured semiconductors, photoinduced electron transfer and transport, and surface catalysis are also described.
- 2Xiang, C.; Weber, A. Z.; Ardo, S.; Berger, A.; Chen, Y.; Coridan, R.; Fountaine, K. T.; Haussener, S.; Hu, S.; Liu, R. Modeling, Simulation, and Implementation of Solar-Driven Water-Splitting Devices. Angew. Chem., Int. Ed. 2016, 55, 12974– 12988, DOI: 10.1002/anie.201510463[Crossref], [PubMed], [CAS], Google Scholar2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28Xht1GjurvP&md5=4f5a99d8d6d5b3e1a84a48daf9e0f7acModeling, Simulation, and Implementation of Solar-Driven Water-Splitting DevicesXiang, Chengxiang; Weber, Adam Z.; Ardo, Shane; Berger, Alan; Chen, YiKai; Coridan, Robert; Fountaine, Katherine T.; Haussener, Sophia; Hu, Shu; Liu, Rui; Lewis, Nathan S.; Modestino, Miguel A.; Shaner, Matthew M.; Singh, Meenesh R.; Stevens, John C.; Sun, Ke; Walczak, KarlAngewandte Chemie, International Edition (2016), 55 (42), 12974-12988CODEN: ACIEF5; ISSN:1433-7851. (Wiley-VCH Verlag GmbH & Co. KGaA)A review is presented. An integrated cell for the solar-driven splitting of water consists of multiple functional components and couples various photoelectrochem. (PEC) processes at different length and time scales. The overall solar-to-hydrogen (STH) conversion efficiency of such a system depends on the performance and materials properties of the individual components as well as on the component integration, overall device architecture, and system operating conditions. This Review focuses on the modeling- and simulation-guided development and implementation of solar-driven water-splitting prototypes from a holistic viewpoint that explores the various interplays between the components. The underlying physics and interactions at the cell level is are reviewed and discussed, followed by an overview of the use of the cell model to provide target properties of materials and guide the design of a range of traditional and unique device architectures.
- 3Fujishima, A.; Honda, K. Electrochemical Photolysis of Water at a Semiconductor Electrode. Nature 1972, 238, 37– 38, DOI: 10.1038/238037a0[Crossref], [PubMed], [CAS], Google Scholar3https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaE38XltVykurw%253D&md5=71f39843802b5cdb5f7cb0deb7f0c63cElectrochemical photolysis of water at a semiconductor electrodeFujishima, Akira; Honda, KenichiNature (London, United Kingdom) (1972), 238 (5358), 37-8CODEN: NATUAS; ISSN:0028-0836.For electrochem. decompn. of H2O, a p.d. of >1.23 V is necessary between the anode and the cathode. This p.d. is equal to the energy of radiation with wavelength of ∼1000 nm. This energy, in the form of visible light, can be used effectively in an electrochem. system to decomp. H2O. A novel type of electrochem. cell was developed, in which a TiO2 electrode was connected with a Pt-black electrode through an external load. The direction of current revealed that oxidn. occurred at the TiO2 electrode and redn. at the Pt-black electrode. To increase the efficiency of the process, more reducible species, such as dissolved O2 or Fe3+, must be added in the Pt electrode compartment. The use of a p-type semiconductor electrode instead of Pt leads to more effective electrochem. photolysis of H2O.
- 4Khaselev, O.; Turner, J. A. A Monolithic Photovoltaic-Photoelectrochemical Device for Hydrogen Production via Water Splitting. Science 1998, 280, 425– 427, DOI: 10.1126/science.280.5362.425[Crossref], [PubMed], [CAS], Google Scholar4https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1cXivVeltro%253D&md5=52b2fa32c45301e05d032c8a711acbd9A monolithic photovoltaic-photoelectrochemical device for hydrogen production via water splittingKhaselev, Oscar; Turner, John A.Science (Washington, D. C.) (1998), 280 (5362), 425-427CODEN: SCIEAS; ISSN:0036-8075. (American Association for the Advancement of Science)Direct water electrolysis was achieved with a novel, integrated, monolithic photoelectrochem.-photovoltaic design. This photoelectrochem. cell, which is voltage biased with an integrated photovoltaic device, splits water directly upon illumination; light is the only energy input. The hydrogen prodn. efficiency of this system, based on the short-circuit current and the lower heating value of hydrogen, is 12.4 percent.
- 5May, M. M.; Lewerenz, H. J.; Lackner, D.; Dimroth, F.; Hannappel, T. Efficient Direct Solar-to-Hydrogen Conversion by in Situ Interface Transformation of a Tandem Structure. Nat. Commun. 2015, 6, 8286, DOI: 10.1038/ncomms9286[Crossref], [PubMed], [CAS], Google Scholar5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsFeis7zM&md5=f212b3a28f4739c128181f8fc3287b7dEfficient direct solar-to-hydrogen conversion by in situ interface transformation of a tandem structureMay, Matthias M.; Lewerenz, Hans-Joachim; Lackner, David; Dimroth, Frank; Hannappel, ThomasNature Communications (2015), 6 (), 8286CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)Photosynthesis is nature's route to convert intermittent solar irradn. into storable energy, while its use for an industrial energy supply is impaired by low efficiency. Artificial photosynthesis provides a promising alternative for efficient robust carbon-neutral renewable energy generation. The approach of direct hydrogen generation by photoelectrochem. water splitting utilizes customized tandem absorber structures to mimic the Z-scheme of natural photosynthesis. Here a combined chem. surface transformation of a tandem structure and catalyst deposition at ambient temp. yields photocurrents approaching the theor. limit of the absorber and results in a solar-to-hydrogen efficiency of 14%. The potentiostatically assisted photoelectrode efficiency is 17%. Present benchmarks for integrated systems are clearly exceeded. Details of the in situ interface transformation, the electronic improvement and chem. passivation are presented. The surface functionalization procedure is widely applicable and can be precisely controlled, allowing further developments of high-efficiency robust hydrogen generators.
- 6Young, J. L.; Steiner, M. A.; Döscher, H.; France, R. M.; Turner, J. A.; Deutsch, T. G. Direct Solar-to-Hydrogen Conversion via Inverted Metamorphic Multi-Junction Semiconductor Architectures. Nature Energy 2017, 2, 17028, DOI: 10.1038/nenergy.2017.28[Crossref], [CAS], Google Scholar6https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXot1ykuro%253D&md5=04ac8805e7de2455968709947216ebbcDirect solar-to-hydrogen conversion via inverted metamorphic multi-junction semiconductor architecturesYoung, James L.; Steiner, Myles A.; Doscher, Henning; France, Ryan M.; Turner, John A.; Deutsch, Todd G.Nature Energy (2017), 2 (4), 17028CODEN: NEANFD; ISSN:2058-7546. (Nature Publishing Group)Solar water splitting via multi-junction semiconductor photoelectrochem. cells provides direct conversion of solar energy to stored chem. energy as hydrogen bonds. Economical hydrogen prodn. demands high conversion efficiency to reduce balance-of-systems costs. For sufficient photovoltage, water-splitting efficiency is proportional to the device photocurrent, which can be tuned by judicious selection and integration of optimal semiconductor bandgaps. Here, we demonstrate highly efficient, immersed water-splitting electrodes enabled by inverted metamorphic epitaxy and a transparent graded buffer that allows the bandgap of each junction to be independently varied. Voltage losses at the electrolyte interface are reduced by 0.55 V over traditional, uniformly p-doped photocathodes by using a buried p-n junction. Advanced on-sun benchmarking, spectrally cor. and validated with incident photon-to-current efficiency, yields over 16% solar-to-hydrogen efficiency with GaInP/GaInAs tandem absorbers, representing a 60% improvement over the classical, high-efficiency tandem III-V device.
- 7Lichterman, M. F.; Sun, K.; Hu, S.; Zhou, X.; McDowell, M. T.; Shaner, M. R.; Richter, M. H.; Crumlin, E. J.; Carim, A. I.; Saadi, F. H. Protection of Inorganic Semiconductors for Sustained, Efficient Photoelectrochemical Water Oxidation. Catal. Today 2016, 262, 11– 23, DOI: 10.1016/j.cattod.2015.08.017[Crossref], [CAS], Google Scholar7https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsVCnu77L&md5=9a11b7d506e8d68dd30bcc3f6907d7deProtection of inorganic semiconductors for sustained, efficient photoelectrochemical water oxidationLichterman, Michael F.; Sun, Ke; Hu, Shu; Zhou, Xinghao; McDowell, Matthew T.; Shaner, Matthew R.; Richter, Matthias H.; Crumlin, Ethan J.; Carim, Azhar I.; Saadi, Fadl H.; Brunschwig, Bruce S.; Lewis, Nathan S.Catalysis Today (2016), 262 (), 11-23CODEN: CATTEA; ISSN:0920-5861. (Elsevier B.V.)A review is presented. Small-band-gap (Eg < 2 eV) semiconductors must be stabilized for use in integrated devices that convert solar energy into the bonding energy of a reduced fuel, specifically H2(g) or a reduced-carbon species such as CH3OH or CH4. To sustainably and scalably complete the fuel cycle, electrons must be liberated through the oxidn. of water to O2(g). Strongly acidic or strongly alk. electrolytes are needed to enable efficient and intrinsically safe operation of a full solar-driven water-splitting system. However, under water-oxidn. conditions, the small-band-gap semiconductors required for efficient cell operation are unstable, either dissolving or forming insulating surface oxides. We describe herein recent progress in the protection of semiconductor photoanodes under such operational conditions. We specifically describe the properties of two protective overlayers, TiO2/Ni and NiOx, both of which have demonstrated the ability to protect otherwise unstable semiconductors for >100 h of continuous solar-driven water oxidn. when in contact with a highly alk. aq. electrolyte (1.0 M KOH(aq)). The stabilization of various semiconductor photoanodes is reviewed in the context of the electronic characteristics and a mechanistic anal. of the TiO2 films, along with a discussion of the optical, catalytic, and electronic nature of NiOx films for stabilization of semiconductor photoanodes for water oxidn.
- 8Bae, D.; Pedersen, T.; Seger, B.; Iandolo, B.; Hansen, O.; Vesborg, P. C. K.; Chorkendorff, I. Carrier-Selective P- and N-Contacts for Efficient and Stable Photocatalytic Water Reduction. Catal. Today 2017, 290, 59– 64, DOI: 10.1016/j.cattod.2016.11.028[Crossref], [CAS], Google Scholar8https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhvVygurvL&md5=75480386fbec912085b70707d04b1cb2Carrier-selective p- and n-contacts for efficient and stable photocatalytic water reductionBae, Dowon; Pedersen, Thomas; Seger, Brian; Iandolo, Beniamino; Hansen, Ole; Vesborg, Peter C. K.; Chorkendorff, IbCatalysis Today (2017), 290 (), 59-64CODEN: CATTEA; ISSN:0920-5861. (Elsevier B.V.)The successful realization of carrier-selective contacts for cryst. silicon (c-Si) based device for photocatalytic hydrogen prodn. has been demonstrated. The proposed TiO2 protected carrier-selective contacts resemble a metal-oxide-semiconductor configuration, including a highly-doped nanocryst. silicon (nc-Si) and a tunnel oxide, thereby form a heterostructure with the c-Si substrate. By substituting conventional pn+-junction Si by c-Si/SiOX/nc-Si structure for both front and back contacts we demonstrate a 16% increase in photovoltage (an open circuit voltage of 584 mV under AM 1.5G conditions). TiO2 protected carrier-selective photoelectrodes showed excellent long-term durability in acidic aq. soln. having stable photocurrent output for more than 40 days, implying that the proposed carrier-selective contact is a promising configuration to substitute for the conventional pn-junction based c-Si photocathodes.
- 9Fountaine, K. T.; Lewerenz, H. J.; Atwater, H. A. Efficiency Limits for Photoelectrochemical Water-Splitting. Nat. Commun. 2016, 7, 13706, DOI: 10.1038/ncomms13706[Crossref], [PubMed], [CAS], Google Scholar9https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XitFWns7%252FE&md5=1e8a310493abece8ebf3f925de3e6d3eEfficiency limits for photoelectrochemical water-splittingFountaine, Katherine T.; Lewerenz, Hans Joachim; Atwater, Harry A.Nature Communications (2016), 7 (), 13706CODEN: NCAOBW; ISSN:2041-1723. (Nature Publishing Group)Theor. limiting efficiencies have a crit. role in detg. technol. viability and expectations for device prototypes, as evidenced by the photovoltaics community's focus on detailed balance. However, due to their multicomponent nature, photoelectrochem. devices do not have an equiv. analog to detailed balance, and reported theor. efficiency limits vary depending on the assumptions made. Here we introduce a unified framework for photoelectrochem. device performance through which all previous limiting efficiencies can be understood and contextualized. Ideal and exptl. realistic limiting efficiencies are presented, and then generalized using five representative parameters-semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance and catalytic exchange c.d.-to account for imperfect light absorption, charge transport and catalysis. Finally, we discuss the origin of deviations between the limits discussed herein and reported water-splitting efficiencies. This anal. provides insight into the primary factors that det. device performance and a powerful handle to improve device efficiency.
- 10May, M. M.; Lackner, D.; Ohlmann, J.; Dimroth, F.; van de Krol, R.; Hannappel, T.; Schwarzburg, K. On the Benchmarking of Multi-Junction Photoelectrochemical Fuel Generating Devices. Sustainable Energy Fuels 2017, 1, 492– 503, DOI: 10.1039/C6SE00083E[Crossref], [CAS], Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhs1Crs7vI&md5=7482968770ccc922edea71a64b97e89aOn the benchmarking of multi-junction photoelectrochemical fuel generating devicesMay, Matthias M.; Lackner, David; Ohlmann, Jens; Dimroth, Frank; van de Krol, Roel; Hannappel, Thomas; Schwarzburg, KlausSustainable Energy & Fuels (2017), 1 (3), 492-503CODEN: SEFUA7; ISSN:2398-4902. (Royal Society of Chemistry)Photoelectrochem. solar fuel generation is evolving steadily towards devices mature for applications, driven by the development of efficient multi-junction devices. The crucial characteristics deciding over feasibility of an application are efficiency and stability. Benchmarking and reporting routines for these characteristics are, however, not yet on a level of standardisation as in the photovoltaic community, mainly due to the intricacies of the photoelectrochem. dimension. We discuss best practice considerations for benchmarking and propose an alternative efficiency definition that includes stability. Furthermore, we analyze the effects of spectral shaping and anti-reflection properties introduced by catalyst nanoparticles and their impact on design criteria for direct solar fuel generation in monolithic devices.
- 11Sathre, R.; Scown, C. D.; Morrow, W. R.; Stevens, J. C.; Sharp, I. D.; Ager, J. W., III; Walczak, K. A.; Houle, F. A.; Greenblatt, J. B. Life-Cycle Net Energy Assessment of Large-Scale Hydrogen Production via Photoelectrochemical Water Splitting. Energy Environ. Sci. 2014, 7, 3264– 3278, DOI: 10.1039/C4EE01019A[Crossref], [CAS], Google Scholar11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhtVylsrzI&md5=4c31f8dca23355d5c9735bc3c2ee1643Life-cycle net energy assessment of large-scale hydrogen production via photoelectrochemical water splittingSathre, Roger; Scown, Corinne D.; Morrow, William R., III; Stevens, John C.; Sharp, Ian D.; Ager, Joel W., III; Walczak, Karl; Houle, Frances A.; Greenblatt, Jeffery B.Energy & Environmental Science (2014), 7 (10), 3264-3278CODEN: EESNBY; ISSN:1754-5706. (Royal Society of Chemistry)Here we report a prospective life-cycle net energy assessment of a hypothetical large-scale photoelectrochem. (PEC) hydrogen prodn. facility with energy output equiv. to 1 GW continuous annual av. (1 GW HHV = 610 metric tons of H2 per day). We det. essential mass and energy flows based on fundamental principles, and use heuristic methods to conduct a preliminary engineering design of the facility. We then develop and apply a parametric model describing system-wide energy flows assocd. with the prodn., utilization, and decommissioning of the facility. Based on these flows, we calc. and interpret life-cycle net energy metrics for the facility. We find that under base-case conditions the energy payback time is 8.1 years, the energy return on energy invested (EROEI) is 1.7, and the life-cycle primary energy balance over the 40 years projected service life of the facility is +500 PJ. The most important model parameters affecting the net energy metrics are the solar-to-hydrogen (STH) conversion efficiency and the life span of the PEC cells; parameters assocd. with the balance of systems (BOS), including construction and operation of the liq. and gas handling infrastructure, play a much smaller role.
- 12Dimroth, F.; Beckert, R.; Meusel, M.; Schubert, U.; Bett, A. W. Metamorphic GayIn1-YP/Ga1-XInXAs Tandem Solar Cells for Space and for Terrestrial Concentrator Applications at C > 1000 Suns. Prog. Photovoltaics 2001, 9, 165– 178, DOI: 10.1002/pip.362[Crossref], [CAS], Google Scholar12https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXksVyqsr8%253D&md5=4ac280908456fc7ffa7c2367c6819267Metamorphic GayIn1-yP/Ga1-xInxAs tandem solar cells for space and for terrestrial concentrator applications at C>1000 sunsDimroth, F.; Beckert, R.; Meusel, M.; Schubert, U.; Bett, A. W.Progress in Photovoltaics (2001), 9 (3), 165-178CODEN: PPHOED; ISSN:1062-7995. (John Wiley & Sons Ltd.)The use of Ga1-xInxAs instead of GaAs as a bottom solar cell in a GayIn1-yP/Ga1-xInxAs tandem structure increases the flexibility of choosing the optimum band-gap combination of materials for a multijunction solar cell. Higher theor. efficiencies are calcd. and different cell concepts are suggested for space and terrestrial concentrator applications. Various GayIn1-yP/Ga1-xInxAs material combinations have been investigated for the first time and efficiencies up to 24.1% (AM0) and 27.0% (AM1.5 direct) have been reached under one-sun conditions. An efficiency of 30.0-31.3% was measured for a Ga0.35In0.65P/Ga0.83In0.17As tandem concentrator cell with prismatic cover at 300 suns. The top and bottom cell layers of this structure are grown lattice-matched to each other, but a large mismatch is introduced at the interface to the GaAs substrate. This cell structure is well suited for the use in next-generation terrestrial concentrators working at high concn. ratios. For the first time a cell efficiency up to 29-30% has been measured at concn. levels up to 1300 suns. A small prototype concentrator with Fresnel lenses and four tandem solar cells working at C=120 has been constructed, with an outdoor efficiency of 23%.
- 13Ohlmann, J.; Sanchez, J. F. M.; Lackner, D.; Förster, P.; Steiner, M.; Fallisch, A.; Dimroth, F. Recent Development in Direct Generation of Hydrogen Using Multi-Junction Solar Cells. AIP Conf. Proc. 2016, 1766, 080004, DOI: 10.1063/1.4962102[Crossref], [CAS], Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XhsVyqurvO&md5=a9060220eb1d4a62e4309ce94f70cf29Recent development in direct generation of hydrogen using multi-junction solar cellsOhlmann, Jens; Sanchez, Juan Francisco Martinez; Lackner, David; Foerster, Paul; Steiner, Marc; Fallisch, Arne; Dimroth, FrankAIP Conference Proceedings (2016), 1766 (1, 12th International Conference on Concentrator Photovoltaic Systems, 2016), 080004/1-080004/6CODEN: APCPCS; ISSN:0094-243X. (American Institute of Physics)Hydrogen produced from solar energy has a high potential as a storage medium to buffer the fluctuations of renewable energy sources. The direct combination of concentrator photovoltaics with an electrolyzer has the capability to produce Hydrogen from sunlight at high efficiency. For this, the individual components have to be adjusted carefully and optimized with the final system in mind. This paper focuses on the solar cell development and shows first results of the combined module of a solar cell and an electrolyzer. The solar cell used for hydrogen prodn. is a metamorphic GaInP/GaInAs dual-junction solar cell. This tandem cell reaches a max. efficiency of 34.2% under concn. The performance of the combined module shows a strong influence of temp. and DNI. (c) 2016 American Institute of Physics.
- 14Porter, J. D.; Heller, A.; Aspnes, D. E. Experiment and Theory of “Transparent” Metal Films. Nature 1985, 313, 664– 666, DOI: 10.1038/313664a0[Crossref], [CAS], Google Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2MXhsVWls7w%253D&md5=c2973e6ccfa8b25ab8b0987dddead80fExperiment and theory of 'transparent' metal filmsPorter, John D.; Heller, Adam; Aspnes, David E.Nature (London, United Kingdom) (1985), 313 (6004), 664-6CODEN: NATUAS; ISSN:0028-0836.Previous evidence (H., 1984) that Pt layers on p-InP are effectively transparent to incident light or even promote the coupling of incident radiation into the bulk of the semiconductor is explained in terms of microstructure: when the metal films are sufficiently porous and built up from particles smaller than the wavelength of the transmitted light, the photon fields are screened out of the metal phase and are forced into the void structure. This increases the effective refractive index of the layer over that of the ambient and provides a better match with the substrate, while incurring negligible absorption loss.
- 15Degani, Y.; Sheng, T. T.; Heller, A.; Aspnes, D. E.; Studna, A. A.; Porter, J. D. Transparent” Metals: Preparation and Characterization of Light-Transmitting Palladium, Rhodium, and Rhenium Films. J. Electroanal. Chem. Interfacial Electrochem. 1987, 228, 167– 178, DOI: 10.1016/0022-0728(87)80105-5[Crossref], [CAS], Google Scholar15https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaL2sXlvVGqsbo%253D&md5=10821839548581e77265d65201c82774"Transparent" metals: preparation and characterization of light-transmitting palladium, rhodium, and rhenium filmsDegani, Y.; Sheng, T. T.; Heller, A.; Aspnes, D. E.; Studna, A. A.; Porter, J. D.Journal of Electroanalytical Chemistry and Interfacial Electrochemistry (1987), 228 (1-2), 167-78CODEN: JEIEBC; ISSN:0022-0728.The principles that govern the prepn. and properties of transparent Pt films apply also to films of Pd, Rh and Re. Films of these metals, of 42-60 nm thickness, having a metal vol. fraction between 0.3 and 0.5, transmit more light than equiv., dense metal films of identical metal loadings per unit area. The films are prepd. by photoelectrodeposition onto p-InP (100) photocathodes, from ∼5 × 10-5 M solns. of the metal ions in 1M HClO4, under mass-transport limited conditions, at deposition rates of ∼2 nm/h. The transparent Rh, Re and Pd films exhibit their normal catalytic behavior and have normal crystal structures. While the transparent Rh and Pd films, like the bulk metals, are stable in air, the Re films oxidize over a period of days to form films that are either truly amorphous or consist of crystallites of <1 nm diam. The spectroellipsometrically measured dielec. functions of these films in air are analyzed, in the framework of the Bruggeman effective medium approxn., to yield film thicknesses, metal vol. fractions, and mean depolarization factors. The resp. depolarization factors of Rh, Pd, and Re indicate dendritic, particulate, and platelet microstructures, consistent with the structures obsd. by TEM. With the spectroellipsometrically derived, substantially divergent, depolarization factors for the different microstructures, one obtains consistent relations among film thicknesses, metal vol. fractions, and the optical properties. Absorption in tenuous films, of const. metal loading but different microstructures, tends to different finite values strongly dependent on microstructure, in the limit of infinite metal diln.
- 16Sanz, J. M.; Ortiz, D.; Alcaraz de la Osa, R.; Saiz, J. M.; González, F.; Brown, A. S.; Losurdo, M.; Everitt, H. O.; Moreno, F. UV Plasmonic Behavior of Various Metal Nanoparticles in the Near- and Far-Field Regimes: Geometry and Substrate Effects. J. Phys. Chem. C 2013, 117, 19606– 19615, DOI: 10.1021/jp405773p[ACS Full Text], [CAS], Google Scholar16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht12hu7nO&md5=01a1a877dde7db4be5161255688fba15UV Plasmonic Behavior of Various Metal Nanoparticles in the Near- and Far-Field Regimes: Geometry and Substrate EffectsSanz, J. M.; Ortiz, D.; Alcaraz de la Osa, R.; Saiz, J. M.; Gonzalez, F.; Brown, A. S.; Losurdo, M.; Everitt, H. O.; Moreno, F.Journal of Physical Chemistry C (2013), 117 (38), 19606-19615CODEN: JPCCCK; ISSN:1932-7447. (American Chemical Society)The practical efficacy of technol. promising metals for use in UV plasmonics (3-6 eV) is assessed by an exhaustive numerical anal. This begins with ests. of the near- and far-field electromagnetic enhancement factors of isolated hemispherical and spherical metallic nanoparticles deposited on typical dielec. substrates like Al2O3, from which the potential of each metal for plasmonic applications may be ascertained. The UV plasmonic behavior of Al, Cr, Cu, Ga, In, Mg, Pd, Pt, Rh, Ru, Ti, and W was compared with the known behavior of Au and Ag in the visible. After exploring this behavior for each metal as a function of nanoparticle shape and size, the deleterious effect caused by the metal's native oxide is considered, and the potential for applications such as surface-enhanced Raman spectroscopy, accelerated photodegrdn. and photocatalysis is addressed.
- 17Anderson, R. L. Germanium-Gallium Arsenide Heterojunctions. IBM J. Res. Dev. 1960, 4, 283– 287, DOI: 10.1147/rd.43.0283[Crossref], [CAS], Google Scholar17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaF3MXhtF2jug%253D%253D&md5=b0e27dfee4f598aceb0f3b8a94780225Germanium-gallium arsenide heterojunctionsAnderson, R. L.(1960), 4 (), 283-7 ISSN:.The method of M. (cf. preceding abstr.) was used to prep. abrupt monocryst. junctions between 2 different semiconductor materials by depositing Ge epitaxially on Ga-As substrates. The junctions produced exhibited rectification properties. Tunnel junctions were also made. Tentative results of a study of the elec. characteristics of these junctions are presented.
- 18Skorupska, K.; Pettenkofer, C.; Sadewasser, S.; Streicher, F.; Haiss, W.; Lewerenz, H. J. Electronic and Morphological Properties of the Electrochemically Prepared Step Bunched Silicon (111) Surface. Phys. Status Solidi B 2011, 248, 361– 369, DOI: 10.1002/pssb.201046454[Crossref], [CAS], Google Scholar18https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXhtVWqu7s%253D&md5=5db6131b6578e958ce0ddf7d20cdedbbElectronic and morphological properties of the electrochemically prepared step bunched silicon (1 1 1) surfaceSkorupska, K.; Pettenkofer, Ch.; Sadewasser, S.; Streicher, F.; Haiss, W.; Lewerenz, H. J.Physica Status Solidi B: Basic Solid State Physics (2011), 248 (2), 361-369CODEN: PSSBBD; ISSN:0370-1972. (Wiley-VCH Verlag GmbH & Co. KGaA)Topog. and electronic and properties of step bunched Si(1 1 1), prepd. by electrochem. processing in alk. soln., are analyzed. Tapping mode at. force microscopy (TM AFM) anal. shows that one bunched step consists of about 15 at. steps (each 0.314 nm in height) and that the (111) oriented terraces have widths that range from 150 to 250 nm. Scanning tunneling microscopy (STM) expts. show a corrugation of the (1 1 1) terraces with an rms roughness of 0.5-0.8 nm, correlated with etch pits in alk. soln. LEED data show a splitting of the (10) and (01) spot from which a min. terrace width of 4.8 nm have been calcd. in good agreement with the TM AFM data. Kelvin probe force microscopy (KPFM) expts. show a decrease of the contact p.d. (CPD) at and near the edges of steps indicating a more neg. charged surface area. Synchrotron radiation photoelectron spectroscopy (SRPES) on electrochem. and purely chem. prepd. step bunched surfaces is compared. From the Si 2p core level shift, and, in particular, from the onset of the valence band emission, an accumulation layer-type shift is obsd. on the electrochem. prepd. sample that is absent for chem. prepn. The move of the Fermi level toward the conduction band min. of the electrochem. conditioned samples is interpreted by H incorporation and discussed by a doping model that involves the mechanism of hydrogen evolution.
- 19Rizk, R.; de Mierry, P.; Ballutaud, D.; Aucouturier, M.; Mathiot, D. Hydrogen Diffusion and Passivation Processes in P- And N-Type Crystalline Silicon. Phys. Rev. B: Condens. Matter Mater. Phys. 1991, 44, 6141– 6151, DOI: 10.1103/PhysRevB.44.6141[Crossref], [PubMed], [CAS], Google Scholar19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK3MXmt1Sisro%253D&md5=502e3248d7584091f5466cdba455882bHydrogen diffusion and passivation processes in p- and n-type crystalline siliconRizk, R.; De Mierry, P.; Ballutaud, D.; Aucouturier, M.; Mathiot, D.Physical Review B: Condensed Matter and Materials Physics (1991), 44 (12), 6141-51CODEN: PRBMDO; ISSN:0163-1829.Several deuteration expts. on cryst. silicon have been performed for various shallow dopant impurities (B and Al for p-type silicon; P and As for n-type silicon) and for different temps. and times of plasma exposure. Deuterium diffusion depth profiles obtained by SIMS were simulated with an improved version of a previously reported model. A careful anal. of the SIMS data has allowed the redn. of the no. of fit parameters, by excluding the H2 mol. formation and by a rough est. of the neutral-deuterium diffusion coeff. and of the surface concn. of neutral deuterium. The diffusion coeffs. and related activation energies of the hydrogen species H0, H-, and H+ were detd., leading to a stated ranking of the mobilities in the order H0 < H- < H+. The dissocn. energies of BH, AlH, and PH complexes were also calcd. and have allowed the authors to deduce the corresponding bonding energies of the complexes, which suggest a scaling of the complex stability in the order PH < BH < AlH. Free-carrier depth profiles obtained by high-frequency capacitance-voltage measurements, combined with chem. etching, provided direct evidence of the rate of passivation of the shallow p-type-dopant impurities. The comparison between both couples of depth profiles (deuterium diffusion and carrier concns.), in the case of p-type silicon, showed good agreement between the deactivation process of dopants and the corresponding depth penetration of deuterium.
- 20Zhang, Y.; Pluchery, O.; Caillard, L.; Lamic-Humblot, A.-F.; Casale, S.; Chabal, Y. J.; Salmeron, M. B. Sensing the Charge State of Single Gold Nanoparticles via Work Function Measurements. Nano Lett. 2015, 15, 51– 55, DOI: 10.1021/nl503782s[ACS Full Text], [CAS], Google Scholar20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitVClsL3O&md5=9ee388f8e69328cff05bb27ecd3b5732Sensing the Charge State of Single Gold Nanoparticles via Work Function MeasurementsZhang, Yingjie; Pluchery, Olivier; Caillard, Louis; Lamic-Humblot, Anne-Felicie; Casale, Sandra; Chabal, Yves J.; Salmeron, MiquelNano Letters (2015), 15 (1), 51-55CODEN: NALEFD; ISSN:1530-6984. (American Chemical Society)Electrostatic interactions at the nanoscale can lead to novel properties and functionalities that bulk materials and devices do not have. Here the authors used Kelvin probe force microscopy (KPFM) to study the work function (WF) of Au nanoparticles (NPs) deposited on a Si wafer covered by a monolayer of alkyl chains, which provide a tunnel junction. The WF of Au NPs is size-dependent and deviates strongly from that of the bulk Au. The authors attribute the WF change to the charging of the NPs, which is a consequence of the difference in WF between Au and the substrate. For an NP with 10 nm diam. charged with ∼5 electrons, the WF is only ∼3.6 eV. A classical electrostatic model is derived that explains the observations in a quant. way. Also the WF and charge state of Au NPs are influenced by chem. changes of the underlying substrate. Therefore, Au NPs could be used for chem. and biol. sensing, whose environmentally sensitive charge state can be read out by work function measurements.
Supporting Information
ARTICLE SECTIONSThe Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsenergylett.8b00920.
Device fabrication; materials characterization techniques; TiO2 characterization; surface layer band alignment; absorption enhancement by TiO2; optimization of the optical design; assessment of the solar-to-hydrogen efficiency measurement; comparative PEC test conditions and results; surface tension variation between pH 0 and 7; X-ray photoelectron spectra and mechanism development; and STH benchmarks (PDF)
Terms & Conditions
Electronic Supporting Information files are available without a subscription to ACS Web Editions. The American Chemical Society holds a copyright ownership interest in any copyrightable Supporting Information. Files available from the ACS website may be downloaded for personal use only. Users are not otherwise permitted to reproduce, republish, redistribute, or sell any Supporting Information from the ACS website, either in whole or in part, in either machine-readable form or any other form without permission from the American Chemical Society. For permission to reproduce, republish and redistribute this material, requesters must process their own requests via the RightsLink permission system. Information about how to use the RightsLink permission system can be found at http://pubs.acs.org/page/copyright/permissions.html.