Thursday, January 17, 20192:00 PM - 3:00 PMCNLS Conference Room (TA-3, Bldg 1690)|
Polaron Behaviors in Hybrid Lead-halide Perovskites Understood
Abstract: Despite state-of-the-art hybrid organic-inorganic perovskites demonstrating great achievements in solar cells, light-emitting devices and photodetectors, the inherently poor instability under ambient conditions impedes their practical use. Here, I will report in-depthcomputational studies of small polaron formation on pure halid perovskite, such a CsPbI3, MAPbI3, FAPbI3, etc. Recently, mixed-cation perovskites promise enhanced performances concerning stability and efficiency in optoelectronic devices. Inspired by this point, here I will also present the polaron behaviors in mixed-cation perovskites soas to explore the impact of coupling of charge carriers to local lattice distortions. Luckily, cation-alloying significantly reduces the polaronbinding energies both for holes and electrons by about a factor of two compared to pure MAPbI3. Delocalized polarons shall have a reduceddetrimental effect on the charge collection in halide perovskite devices. These results can guide future development of halide perovskites for optoelectronic applications.
Host: David Metiver