Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University , Suzhou, Jiangsu 215123 China.
Nano Lett. 2016 Jul 13;16(7):4720-5. doi: 10.1021/acs.nanolett.6b02307. Epub 2016 Jun 30.
Organic-inorganic lead perovskites have shown great promise as photovoltaic materials, and within this class of materials (CH3NH3)PbI3-xClx is of particular interest. Herein we use soft X-ray spectroscopy and density functional theory calculations to demonstrate that the methylammonium cations in a typical photovoltaic layer may dissociate into a metastable arrangement of CH3I-Pb2 defects and trapped NH3. The possibility that other metastable configurations of the organic components in (CH3NH3)PbI3-xClx is rarely considered but adds an entirely new dimension in understanding the charge trapping, ionic transport, and structural degradation mechanisms in these materials. Understanding the influence of these other configurations is of critical importance for further improving the performance of these photovoltaics.
有机-无机铅卤钙钛矿作为光伏材料表现出巨大的潜力，而在这类材料中（CH3NH3）PbI3-xClx 尤为引人关注。本文通过软 X 射线谱和密度泛函理论计算证明，典型光伏层中的甲胺阳离子可能会离解成 CH3I-Pb2 缺陷和被捕获的 NH3 的亚稳排列。其他亚稳构型的可能性在（CH3NH3）PbI3-xClx 中很少被考虑，但在理解这些材料中的电荷俘获、离子输运和结构降解机制方面增加了全新的维度。理解这些其他构型的影响对于进一步提高这些光伏材料的性能至关重要。
