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Example:10.1021/acsami.1c06204 or Chem. Rev., 2007, 107, 2411-2502
The critical role of composition-dependent intragrain planar defects in the performance of MA1–xFAxPbI3 perovskite solar cells
Nature Energy  (IF60.858),  Pub Date : 2021-06-14, DOI: 10.1038/s41560-021-00830-9
Wei Li, Mathias Uller Rothmann, Ye Zhu, Weijian Chen, Chenquan Yang, Yongbo Yuan, Yen Yee Choo, Xiaoming Wen, Yi-Bing Cheng, Udo Bach, Joanne Etheridge

Perovskite solar cells show excellent power conversion efficiencies, long carrier diffusion lengths and low recombination rates. This encourages a view that intragrain defects are electronically benign with little impact on device performance. In this study we varied the methylammonium (MA)/formamidinium (FA) composition in MA1xFAxPbI3 (x = 0–1), and compared the structure and density of the intragrain planar defects with device performance, otherwise keeping the device nominally the same. We found that charge carrier lifetime, open-circuit voltage deficit and current density–voltage hysteresis correlate empirically with the density and structure of {111}c planar defects (x = 0.5–1) and {112}t twin boundaries (x = 0–0.1). The best performance parameters were found when essentially no intragrain planar defects were evident (x = 0.2). Similarly, reducing the density of {111}c planar defects through MASCN vapour treatment of FAPbI3 (x ≈ 1) also improved performance. These observations suggest that intragrain defect control can provide an important route for improving perovskite solar cell performance, in addition to well-established parameters such as grain boundaries and interfaces.