Key Laboratory for Micro-Nano Physics and Technology of Hunan Province, State Key Laboratory of Chemo/Biosensing and Chemometrics, School of Physics and Electronics , Hunan University , Changsha 410082 , People's Republic of China.
Suzhou Institute of Nano-tech and Nano-Bionics , Chinese Academy of Sciences , Suzhou 215123 , People's Republic of China.
Nano Lett. 2018 May 9;18(5):3024-3031. doi: 10.1021/acs.nanolett.8b00486. Epub 2018 Apr 30.
Metal halide perovskite nanostructures have recently been the focus of intense research due to their exceptional optoelectronic properties and potential applications in integrated photonics devices. Charge transport in perovskite nanostructure is a crucial process that defines efficiency of optoelectronic devices but still requires a deep understanding. Herein, we report the study of the charge transport, particularly the drift of minority carrier in both all-inorganic CsPbBr and organic-inorganic hybrid CHNHPbBr perovskite nanoplates by electric field modulated photoluminescence (PL) imaging. Bias voltage dependent elongated PL emission patterns were observed due to the carrier drift at external electric fields. By fitting the drift length as a function of electric field, we obtained the carrier mobility of about 28 cm V S in the CsPbBr perovskite nanoplate. The result is consistent with the spatially resolved PL dynamics measurement, confirming the feasibility of the method. Furthermore, the electric field modulated PL imaging is successfully applied to the study of temperature-dependent carrier mobility in CsPbBr nanoplates. This work not only offers insights for the mobile carrier in metal halide perovskite nanostructures, which is essential for optimizing device design and performance prediction, but also provides a novel and simple method to investigate charge transport in many other optoelectronic materials.
金属卤化物钙钛矿纳米结构由于其优异的光电性能和在集成光子学器件中的潜在应用，最近成为了研究的热点。钙钛矿纳米结构中的电荷输运是决定光电设备效率的关键过程，但仍需要深入理解。在此，我们通过电场调制光致发光（PL）成像研究了电荷输运，特别是在全无机 CsPbBr 和有机-无机杂化 CHNHPbBr 钙钛矿纳米板中少数载流子的漂移。由于外部电场中的载流子漂移，观察到了与偏置电压相关的拉长的 PL 发射图案。通过拟合漂移长度作为电场的函数，我们获得了 CsPbBr 钙钛矿纳米板中约 28 cm V S 的载流子迁移率。该结果与空间分辨 PL 动力学测量一致，证实了该方法的可行性。此外，电场调制 PL 成像成功应用于 CsPbBr 纳米板中载流子迁移率随温度变化的研究。这项工作不仅为金属卤化物钙钛矿纳米结构中的移动载流子提供了深入的了解，这对于优化器件设计和性能预测至关重要，而且还为研究许多其他光电材料中的电荷输运提供了一种新颖而简单的方法。
