Organolead halide perovskites have emerged as exciting optoelectronic materials but a complete understanding of their photophysical properties is still lacking. Here, a morphological series of methylammonium lead bromide (MAPbBr₃) perovskites are studied by transient optical spectroscopies over eight orders of magnitude in timescale to investigate the effect of nanostructuring and surface states on the charge carrier dynamics. The sample preparation route and corresponding morphology changes influence the position of the optical features, recombination dynamics, excitation fluence dependence, and dramatically impact surface trap passivation. Growth of the perovskite layer in the presence of capping ligands or within mesoporous alumina increases the photoluminescence efficiency by multiple orders of magnitude, indicating that interfacing with metal oxides can lead to the passivation of surface nonradiative recombination centers. Nanoparticles (NPs) dispersed in solution show mixed behavior since they consist of NPs on nanoplatelets, while isolated NPs could be grown within mesoporous alumina with the addition of capping ligands. Investigation on the microsecond timescale suggests that an exponential distribution of states below the band edges results in long‐lived charges. The investigations of the relationship between sample architecture and charge carrier dynamics will help in the appropriate choice of perovskite morphology for use in optoelectronic devices.

中文翻译：

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具有封端配体和金属氧化物界面的有机油卤化物钙钛矿中电荷载流子动力学和表面钝化的调谐。

有机油卤化物钙钛矿已成为令人兴奋的光电材料，但仍缺乏对其光物理性质的完整理解。这里是甲基铵溴化铅（MAPbBr ₃钙钛矿是通过在时间尺度上超过八个数量级的瞬态光学光谱学研究的，以研究纳米结构和表面状态对电荷载流子动力学的影响。样品制备路线和相应的形态变化会影响光学特征的位置，重组动力学，激发通量依赖性以及对表面陷阱钝化的显着影响。在封端配体的存在下或在介孔氧化铝中钙钛矿层的生长将光致发光效率提高了多个数量级，这表明与金属氧化物的界面可导致表面非辐射复合中心的钝化。分散在溶液中的纳米颗粒（NP）具有混合行为，因为它们由纳米片上的NP组成，分离的NPs可以在中孔氧化铝中添加封端配体来生长。对微秒时标的研究表明，能带边缘以下状态的指数分布会导致长寿命电荷。对样品结构和电荷载流子动力学之间关系的研究将有助于正确选择钙钛矿形态用于光电器件。