Spectral Instability of Layered Mixed Halide Perovskites Results from Anion Phase Redistribution and Selective Hole Injection
- 주제(키워드) mixed halide perovskite , perovskite light-emitting diode , ion migration , halide redistribution , spectral instability
- 주제(기타) Chemistry, Multidisciplinary
- 주제(기타) Chemistry, Physical
- 주제(기타) Nanoscience & Nanotechnology
- 주제(기타) Materials Science, Multidisciplinary
- 설명문(일반) [Nah, Yoonseo; Kim, Dong Ha] Ewha Womans Univ, Coll Engn, Div Chem Engn & Mat Sci, Seoul 03760, South Korea; [Allam, Omar] Georgia Inst Technol, George W Woodruff Sch Mech Engn, Atlanta, GA 30332 USA; [Allam, Omar; Choi, Ji Il; Jang, Seung Soon] Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA; [Kim, Han Seul] Korea Inst Sci & Technol Informat, Natl Inst Supercomp & Networking, Ctr Supercomp Applicat, Daejeon 34141, South Korea; [Kim, In Soo] Korea Inst Sci & Technol, Nanophoton Res Ctr, Seoul 02792, South Korea; [Byun, Jinwoo; Kim, Sang Ouk] Korea Adv Inst Sci & Technol, Dept Mat Sci & Engn, Daejeon 34141, South Korea; [Byun, Jinwoo; Kim, Sang Ouk] Korea Adv Inst Sci & Technol, Natl Creat Res Initiat Ctr Multidimens Directed N, Daejeon 34141, South Korea; [Kim, Dong Ha] Ewha Womans Univ, Coll Nat Sci, Dept Chem & Nano Sci, Div Mol & Life Sci, Seoul 03760, South Korea
- 등재 SCIE, SCOPUS
- 발행기관 AMER CHEMICAL SOC
- 발행년도 2021
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000181388
- 본문언어 영어
- Published As http://dx.doi.org/10.1021/acsnano.0c08897
초록/요약
Despite the ability to precisely tune their bandgap energies, mixed halide perovskites (MHPs) suffer from significant spectral instability, which obstructs their utilization for the rational design of light-emitting diodes. Here, we investigate the origin of the electroluminescence peak shifts in layered MHPs containing bromide and iodide. X-ray diffraction and steady-state absorption measurements prove effective integration of iodide into the cubic lattice and the spatially uniform distribution of halides in the ambient environment. However, the applied electric field during the device operation is found to drive the systematic halide migration. Quantum mechanical density functional theory calculations reveal that the different activation energies required for directional ion hopping lead to the redistribution of anions. In-depth analyses of the electroluminescence spectra indicate that the spectral shifting rate is dependent on the drift velocity of halides. Finally, it is suggested from our study that the dominant red emission is ascribed to the thermodynamically favorable selective hole injection. Our mechanistic study provides insights into the fundamental reason for the spectral instability of devices based on MHPs.
more