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.

中文翻译：

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离子迁移修复CH ₃ NH ₃ PbBr ₃钙钛矿中的捕集中心

我们调查了甲基铵溴化铅（MAPbBr ₃）在照明下的钙钛矿晶体。我们的结果表明，与非均匀区域的发射相比，结构均匀区域的发射呈蓝移。结构上均匀的区域的发射的产量和光谱不随照明时间而变化，而在不均匀区域的光谱中可见明显的光诱导变化。长时间照射后光谱的变化表明，离子迁移会抑制非均匀区域的发射。发射寿命的测量表明，来自不均匀区域的发射主要由短照射时间的缺陷相关发射和较长照射时间的带间发射组成。我们的工作为光诱导的缺陷中心愈合提供了直接的证据，₃。