Aligned Crystalline Silicon (ACSi)

Technology Marketing SummaryThis technology, which produces thin films that approach the high-performance aspects of single-crystalline silicon, has been proven and replicated in the laboratory and results have been published in a peer-reviewed journal [Findikoglu et al., Adv. Mater. 17, 1527 (2005)].DescriptionLos Alamos National Laboratory (LANL) has applied its ion beam assisted deposition (IBAD) texturing technology to solving a significant problem that commonly arises during development of many thin-film semiconductor sensor and device applications -- the lack of a suitable epitaxial template for the growth of well-oriented films. Most cases require single-crystal templates that are usually expensive and/or available for only a limited number of materials. For example, photovoltaic energy conversion efficiency for expensive solar cells that use bulk, single-crystalline silicon can exceed 24%, whereas inexpensive solar cells based on amorphous silicon films seldom surpass 8% efficiency. Thus, a technology that allows one to approach the efficiency of single-crystalline silicon with the cost advantages of thin film architectures should be very useful to the industry. We recently demonstrated growth of nearly single-crystalline, high-carrier-mobility, Si thin films on flexible, polycrystalline, metal-alloy tapes by incorporating an ion-beam-textured buffer layer.Benefits

• Optimizes performance/cost compared with high-performance, high-cost single-crystal wafer and low-performance, low-cost amorphous film solar cells.
• Potential for high efficiency, high-performance, low cost, low weight solar cells.
• Customizable to specific application, adaptable to evolving technology.
• Manufacturing cost savings, ease of installation.

Applications and Industries

• Solar Cells
• Sensors
• Flat Panels
• IC Circuits

Patents and Patent Applications

ID Number	Title and Abstract	Primary Lab	Date
Patent 7,288,332	Conductive layer for biaxially oriented semiconductor film growth A conductive layer for biaxially oriented semiconductor film growth and a thin film semiconductor structure such as, for example, a photodetector, a photovoltaic cell, or a light emitting diode (LED) that includes a crystallographically oriented semiconducting film disposed on the conductive layer. The thin film semiconductor structure includes: a substrate; a first electrode deposited on the substrate; and a semiconducting layer epitaxially deposited on the first electrode. The first electrode includes a template layer deposited on the substrate and a buffer layer epitaxially deposited on the template layer. The template layer includes a first metal nitride that is electrically conductive and has a rock salt crystal structure, and the buffer layer includes a second metal nitride that is electrically conductive. The semiconducting layer is epitaxially deposited on the buffer layer. A method of making such a thin film semiconductor structure is also described.	Los Alamos National Laboratory	10/30/2007 Issued
Patent 7,781,067	Aligned crystalline semiconducting film on a glass substrate and method of making A semiconducting structure having a glass substrate. In one embodiment, the glass substrate has a softening temperature of at least about 750.degree. C. The structure includes a nucleation layer formed on a surface of the substrate, a template layer deposited on the nucleation layer by one of ion assisted beam deposition and reactive ion beam deposition, at least on biaxially oriented buffer layer epitaxially deposited on the template layer, and a biaxially oriented semiconducting layer epitaxially deposited on the buffer layer. A method of making the semiconducting structure is also described.	Los Alamos National Laboratory	08/24/2010 Issued

Technology Status

Development Stage	Availability	Published	Last Updated
Prototype	Available - We are looking for a licensee or a cooperative research partner to help us develop a complete solar cell prototype using this method.	09/08/2010	04/04/2013