MSE Seminar: Na Sai, University of Texas at Austin

3:00 pm on Friday, January 24, 2014
4:00 pm on Friday, January 24, 2014
8 St. Mary’s Street, Room 205
New Materials for Solar Cells: From Quantum Mechanical Simulations to Computational Materials Design The sun delivers enormous energy to Earth that can meet our current and future demands. Only 0.18% of the total US electricity production is currently derived from sunlight. The enormous gap between the potential for solar energy exploitation and its utilization is due to the cost and inefficiency of existing energy conversion devices. Third-generation solar cells are being designed to meet the grand challenge of making the conversion dramatically more affordable and efficient by innovating in the area of materials and design concepts. Organic semiconductor solar cells offer the prospect of inexpensive and scalable production combined with mechanical flexibility. The design of optimal organic photovoltaics (OPVs) demands elucidation of physical mechanisms in the separation of electrons and holes at organic interfaces and in the transport of charge in organic heterojunctions. Both are critical steps in the energy conversion process and are defined by the unique active material electronic properties. Computational investigations of OPV materials and interfaces predict key electronic properties governing the energy conversion efficiency, such as excited states, energy level alignment, interfacial charge transfer, interfacial dipoles, charge trapping, and the dependence on the molecular structure, interfacial geometry, and morphology. I will discuss strategies for integrating theory with experiment to generate fundamental insight into the role of hot charge transfer excitons and for harnessing materials design to enhance organic photovoltaic performance.