Organolead halide perovskites convert optical excitations to charge carriers with remarkable efficiency in optoelectronic devices. Previous research predominantly documents dynamics in perovskite thin films; however, extensive disorder in this platform may obscure the observed carrier dynamics. Here, carrier dynamics in perovskite single‐domain single crystals is examined by performing transient absorption spectroscopy in a transmissive geometry. Two distinct sets of carrier populations that coexist at the same radiation fluence, but display different decay dynamics, are observed: one dominated by second‐order recombination and the other by third‐order recombination. Based on ab initio simulations, this observation is found to be most consistent with the hypothesis that free carriers and localized carriers coexist due to polaron formation. The calculations suggest that polarons will form in both CH₃NH₃PbBr₃ and CH₃NH₃PbI₃ crystals, but that they are more pronounced in CH₃NH₃PbBr₃. Single‐crystal CH₃NH₃PbBr₃ could represent the key to understanding the impact of polarons on the transport properties of perovskite optoelectronic devices.

中文翻译：

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兴奋剂分成两个不同的散装钙钛矿种群

有机油卤化物钙钛矿将光激发转换为光载流子，在光电器件中具有显着的效率。先前的研究主要记录了钙钛矿薄膜的动力学。然而，该平台的广泛紊乱可能会掩盖观察到的载流子动力学。在这里，钙钛矿单畴单晶中的载流子动力学是通过在透射几何中执行瞬态吸收光谱法来检查的。观察到两组具有相同辐射通量但表现出不同衰减动力学的不同载流子种群：一组由二阶重组控制，另一组由三阶重组控制。根据从头算的模拟，发现该观察结果与以下事实最一致：自由极化子和局部极化子由于极化子的形成而共存。₃ NH ₃ PbBr ₃和CH ₃ NH ₃ PbI ₃晶体，但它们在CH ₃ NH ₃ PbBr ₃中更为明显。CH ₃ NH ₃ PbBr ₃单晶可能代表理解极化子对钙钛矿光电器件传输特性的影响的关键。