Materials Science

Key metrologies/systems: In situ spectroscopic ellipsometry, linear and non-linear spectroscopies/Polymeric thiophene-based semiconductors for flexible large area electronics. Advanced platforms and protocols are being developed towards innovative metrology suites that allow the full characterized the structure-function relationships of polymeric semiconductors, including functionalized thiophene species, under a variety processing conditions.

Optical Characterization of Thin Films

A wide range of technologies are impacted by the performance of thin (<100 nm) layers of advanced materials. This is particularly true in the emerging macroelectronics industry and in biomaterials. Rational development of these materials is hampered by the lack of structure-function relationships due to a severe lack of adequate data/measurement tools for molecular level characterization of thin films. The traditional structural tools of x-ray diffraction and NMR are severely limited due to lack of signal and contrast. The focus of this project is developing and demonstrating the ability of bench-top optical tools, combined with advanced physical models to determine the details of molecular structure in thin films and at interfaces. Specific emphasis is placed on polarized photon spectroscopies: spectroscopic ellipsometry, infrared absorption, broadband ultrafast laser-based sum frequency generation and coherent anti-Stokes Raman scattering.
Link to additional details.

Associated Publications:

“Controlling the Formation an Orientation of Terraced Nanoscale Ribbons of a Thiophene-based copolymer”, submitted to ACS Nano.

 “Thin Film Microstructure of a Solution Processable Pyrene-Based Organic Semiconductor, L.A. Lucas, D.M. DeLongchamp, L.J. Richter, R.J. Kline, D.A. Fischer, B.R. Kaafarani, and G.E. Jabbour,” Chem Mater 2008, 20, 5743-5749.

“Molecular Basis of Mesophase Ordering in a Thiophene-Based Copolymer”, D.M. DeLongchamp, R.J. Kline, Y. Jung, E.K. Lin, D.A. Fischer, D.J. Gundlach, S.K. Cotts, A.J. Moad, L.J. Richter, M.F. Toney, M. Heeney, and I. McCulloch, Macromolecules 2008, 41, 5709-5715.

 “Contact-Induced Crystallinity for High-Performance Soluble Acene-Based Transistors and Circuits”, D.J. Gundlach et al.”, Nature Materials. 2008, 7, 216-221.

“Critical Role of Side-Chain Attachment Density on the Order and Device Performance of Polythiophenes”, R.J. Kline et al., Macromolecules 2007, 40, 7960-7965.