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Chemistry Department Seminar

Date:
-
Location:
CP114A/B
Speaker(s) / Presenter(s):
Dr. John Asbury

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Dr. John Asbury of Penn State will be presenting a seminar titled When Molecules and Materials Clash: Pathways to high efficiency solution processed solar cells

Abstract: Molecules figure prominently in the electronic properties of emerging materials ranging from organic photovoltaics (OPVs) to colloidal quantum dots (CQDs) and organo-halide perovskites used in solution processed photovoltaics and photodetectors. The Asbury group has pioneered the development of ultrafast vibrational spectroscopy techniques to examine electronic processes in materials with particular focus on the influence that underlying molecular structures have on those processes. This talk will focus on two applications of vibrational spectroscopy to examine electronic processes in OPV and CQD photovoltaic materials. In the first application, the influence of molecular structure and material morphology on charge delocalization is correlated with the corresponding quantum yield for charge generation and OPV device performance. In the second application, the surface chemistry of ligand-nanocrystal interactions and their corresponding influences on the density and energetic distribution of charge trap states in CQD photovoltaic materials are examined. Direct observation of the vibrational features of ligands attached to surface trap states provide unique insights into the nature of charge traps and helps define pathways for their elimination. In both cases, the ability to link underlying molecular structures with electrical properties provides unique insights that lead to new design rules in support of continued materials development efforts.

Faculty Host: Dr. Kenneth Graham