Understanding the light and electric field-induced effects underlying the local changes in optoelectronic properties in lead halide perovskites is crucial to establish a detailed structure–function relationship. Here, we use single-molecule absorption scanning tunneling microscopy (SMA-STM) to probe the local surface inhomogeneity of a mixed A-site cation/mixed halide perovskite under pulsed 532 nm photoexcitation to gain insight into the varying grain-to-grain absorption behavior at the nanoscale and reduction in the electronic bandgap under illumination. To correlate the observed changes in the absorption signal to structural ones, we utilize synchrotron X-ray STM (SX-STM) where we find that photoexcitation induces changes in the X-ray absorption spectral signatures. Lastly, using pump–probe time-resolved wide-angle X-ray scattering, we show the presence of nonthermal lattice deformations upon photoexcitation which indicate that the excited photocarriers distort the perovskite lattice, corroborating the local electronic changes observed by our STM measurements.

中文翻译：

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用光和电场强调卤化物钙钛矿

了解卤化铅钙钛矿光电特性局部变化背后的光和电场诱导效应对于建立详细的结构-功能关系至关重要。在这里，我们使用单分子吸收扫描隧道显微镜 (SMA-STM) 在脉冲 532 nm 光激发下探测混合 A 位阳离子/混合卤化物钙钛矿的局部表面不均匀性，以深入了解不同的晶粒间吸收纳米级的行为和照明下电子带隙的减少。为了将观察到的吸收信号变化与结构信号相关联，我们利用同步加速器 X 射线 STM (SX-STM)，我们发现光激发会引起 X 射线吸收光谱特征的变化。最后，使用泵-探针时间分辨广角 X 射线散射，