Linking phase segregation and photovoltaic performance of mixed-halide perovskite films through grain size engineering

Long Hu, Xinwei Guan, Weijian Chen, Yuchen Yao, Tao Wan, Chun-Ho Lin, Ngoc Duy Pham, Lin Yuan, Xun Geng, Fei Wang, Chieng-Yu Huang, Jianyu Yuan, Soshan Cheong, Richard D. Tilley, Xiaoming Wen, Dewei Chu*, Shujuan Huang*, Tom Wu*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Mixed-halide perovskites are attractive candidates as wide-bandgap absorber layers in tandem solar cells. However, photoinduced phase segregation leads to the formation of Br-rich and I-rich domains with uncontrolled composition and bandgap, which is considered as the main obstacle for achieving stable solar cells. Herein, we tune the grain size of CsPbBr1.5I1.5 films derived from nanocrystals and investigate the corresponding charge transport properties. The correlation between phase segregation, grain size, and the corresponding solar cell performance is unravelled. Specifically, phase segregation takes place in CsPbBr1.5I1.5 films with an average crystal size being equal to or larger than 43 nm, which consequently leads to significantly degraded performance in the solar cells with such large grains under continuous light soaking. These findings provide the highly sought-after guidelines for achieving phase-segregation-free mixed-halide perovskite films for stable optoelectronic applications.
[Graphic abstract presents]
Original languageEnglish
Pages (from-to)1649-1658
Number of pages10
JournalACS Energy Letters
Volume6
Issue number4
DOIs
Publication statusPublished - 9 Apr 2021

Fingerprint

Dive into the research topics of 'Linking phase segregation and photovoltaic performance of mixed-halide perovskite films through grain size engineering'. Together they form a unique fingerprint.

Cite this