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arXiv · 2407.04984

Prolonged Phase Segregation of Mixed-Halide Perovskite Nanocrystals in the Dark

Xueying Ma·Yuhui Ye·Yang Xiao·Shengnan Feng·Chunfeng Zhang·Keyu Xia·Fengrui Hu·Min Xiao·Xiaoyong Wang
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Abstract

A critical issue hindering the potential applications of semiconductor mixed-halide perovskites is the phase segregation effect, wherein localized regions enriched with one type of halide anions would be formed upon continuous photogeneration of the excited-state charge carriers. These unexpected phases are capable of remixing again in the dark under the entropic driving force, the process of which are now being exclusively studied after mixed-halide perovskites have arrived at the final stage of complete phase segregation. Here we show that after the removal of laser excitation from a solid film of mixed-halide perovskite nanocrystals with partial phase segregation, the iodide- and bromide-rich regions can continuously grow in the dark for a prolonged time period of several minutes. We propose that this dark phase segregation is sustained by the local electric fields associated with the surface-trapped charge carriers, whose slow dissipation out of mixed-halide perovskite nanocrystals causes a delayed occurrence of the reversal phase remixing process.

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Xueying Ma, Yuhui Ye, Yang Xiao, Shengnan Feng, Chunfeng Zhang, Keyu Xia, Fengrui Hu, Min Xiao, Xiaoyong Wang. 2024-07-06. Prolonged Phase Segregation of Mixed-Halide Perovskite Nanocrystals in the Dark. https://arxiv.org/abs/2407.04984

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