Phase-Transition-Induced Carrier Mass Enhancement in 2D Ruddlesden-Popper Perovskites
Phase-Transition-Induced Carrier Mass Enhancement in 2D Ruddlesden-Popper Perovskites
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DOI：
10.1021/acsenergylett.9b01435
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发表时间：
2019-10-01
影响因子：
22
通讯作者：
Plochocka, Paulina
中科院分区：
文献类型：
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作者：
Baranowski, Michal;Zelewski, Szymon J.;Plochocka, Paulina
有多种可能的方法来调整二维钙钛矿的光学性质，尽管不同调谐参数之间的相互依赖性阻碍了我们对其性质的基本理解。在这项工作中，我们试图在高达67 t的高磁场中使用光谱学解决（CnH2n+1NH3）(2)PbI4 （n = 4,6,8,10,12）的这一问题。我们的实验结果得到DFT计算的支持，清楚地表明激子减少质量在低温阶段增加了约30%。这反映在抗磁系数降低2-3倍上。我们的研究表明，有效质量是光电器件工作的重要参数，可以通过有机间隔的变化和/或使用Peltier冷却器实现的适度冷却来调节。此外，我们表明，在磁场中，吸收/透射光谱中可见的复合吸收特征相互跟踪，为观测到的边带声子相关的性质提供了强有力的证据。
There are a variety of possible ways to tune the optical properties of 2D perovskites, though the mutual dependence among different tuning parameters hinders our fundamental understanding of their properties. In this work, we attempt to address this issue for (CnH2n+1NH3)(2)PbI4 (with n = 4, 6, 8, 10, 12) using optical spectroscopy in high magnetic fields up to 67 T. Our experimental results, supported by DFT calculations, clearly demonstrate that the exciton reduced mass increases by around 30% in the low-temperature phase. This is reflected by a 2-3-fold decrease of the diamagnetic coefficient. Our studies show that the effective mass, which is an essential parameter for optoelectronic device operation, can be tuned by the variation of organic spacers and/or moderate cooling achievable using Peltier coolers. Moreover, we show that the complex absorption features visible in absorption/transmission spectra track each other in a magnetic field, providing strong evidence for the phonon-related nature of the observed side bands.