Ion Migration Heals Trapping Centers in CH₃NH₃PbBr₃ Perovskite

TY - JOUR

T1 - Ion Migration Heals Trapping Centers in CH3NH3PbBr3 Perovskite

AU - Ghosh, Supriya

AU - Pal, Suman Kalyan

AU - Karki, Khadga J.

AU - Pullerits, Tönu

N1 - Publisher Copyright: © 2017 American Chemical Society.

PY - 2017/9/8

Y1 - 2017/9/8

N2 - We investigate the local changes in photophysics at different microregions of a methylammonium lead bromide (MAPbBr3) perovskite crystal under illumination. Our results show that the emission from the structurally homogeneous region is blue-shifted compared to the emission from the inhomogeneous regions. The yield and spectrum of the emission from the structurally homogeneous region do not vary with the illumination time, whereas distinct light-induced changes are seen in the spectra from the inhomogeneous region. The changes in the spectra at long illumination time suggest that ion-migration inhibits the emission from the inhomogeneous regions. The measurements of the emission lifetime suggest that the emission from the inhomogeneous regions is dominated by the defect-related emission at short illumination times and the band-to-band emission at the longer illumination times. Our work provides direct evidence for the light-induced healing of the defect centers, which is important in the design of photoactive devices of MAPbBr3.

AB - We investigate the local changes in photophysics at different microregions of a methylammonium lead bromide (MAPbBr3) perovskite crystal under illumination. Our results show that the emission from the structurally homogeneous region is blue-shifted compared to the emission from the inhomogeneous regions. The yield and spectrum of the emission from the structurally homogeneous region do not vary with the illumination time, whereas distinct light-induced changes are seen in the spectra from the inhomogeneous region. The changes in the spectra at long illumination time suggest that ion-migration inhibits the emission from the inhomogeneous regions. The measurements of the emission lifetime suggest that the emission from the inhomogeneous regions is dominated by the defect-related emission at short illumination times and the band-to-band emission at the longer illumination times. Our work provides direct evidence for the light-induced healing of the defect centers, which is important in the design of photoactive devices of MAPbBr3.

UR - http://www.scopus.com/inward/record.url?scp=85033681815&partnerID=8YFLogxK

U2 - 10.1021/acsenergylett.7b00577

DO - 10.1021/acsenergylett.7b00577

M3 - 文章

AN - SCOPUS:85033681815

SN - 2380-8195

VL - 2

SP - 2133

EP - 2139

JO - ACS Energy Letters

JF - ACS Energy Letters

IS - 9

ER -