Cation Dynamics in Mixed-Cation (MA)x(FA)1–xPbI3 Hybrid Perovskites from Solid-State NMR

作者：Dominik J. Kubicki, Daniel Prochowicz, Albert Hofstetter, Péter Péchy, Shaik M. Zakeeruddin, Michaël Grätzel, Lyndon Emsley · 发表于：Journal of the American Chemical Society · 年份：2017 · DOI：10.1021/jacs.7b04930 · 被引用次数：253 · 研究领域：Perovskite Materials and Applications、Solid-state spectroscopy and crystallography、Organic and Molecular Conductors Research

Mixed-cation organic lead halide perovskites attract unfaltering attention owing to their excellent photovoltaic properties. Currently, the best performing perovskite materials contain multiple cations and provide power conversion efficiencies up to around 22%. Here, we report the first quantitative, cation-specific data on cation reorientation dynamics in hybrid mixed-cation formamidinium (FA)/methylammonium (MA) lead halide perovskites. We use 14 N, 2 H, 13 C, and 1 H solid-state MAS NMR to elucidate cation reorientation dynamics, microscopic phase composition, and the MA/FA ratio, in (MA) x (FA) 1– x PbI 3 between 100 and 330 K. The reorientation rates correlate in a striking manner with the carrier lifetimes previously reported for these materials and provide evidence of the polaronic nature of charge carriers in PV perovskites.