0100476411

open access

Accepted Manuscript

Dynamic Symmetry Conversion in Mixed-Halide Hybrid Perovskite upon Illumination

English (英語)

ACS Energy Letters

6(11)

3858-3863

American Chemical Society

2021-10-12

2022-11-01

Organic–inorganic hybrid halide perovskites (ABX3, where A = CH3NH3+ (methylammonium ion, MA); B = Pb2+; and X = Br–, I–, or Cl–) have excellent optoelectronic properties and are highly efficient photovoltaic materials, but their chemical instability impedes their development for use in next-generation solar cells, wherein they serve as the light-harvesting material. Here, we propose a mechanism of photoluminescence red-shift, a performance-loss phenomenon known as light-induced halide segregation, in mixed-halide perovskites upon illumination using in situ single-particle spectroscopy and synchrotron-based X-ray techniques. Our experimental analyses suggest a defect-assisted photoinduced transition from ordinary nonpolar phases to polar phases at the local scale within seconds is coupled with organic cation reorientation, which in turn narrows the bandgap; first-principles calculations quantitatively supported this result. Our findings provide deeper insights into the nature of local polar domains in hybrid perovskite materials and help improve device stability and efficiency.

学術雑誌論文

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Energy Letters, copyright © 2021 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/articlesonrequest/AOR-TFVCVAEE7P2A6A5CMESE.