Title: Toward long-term stability: single crystal alloys of cesium-containing mixed cations and mixed halides perovskite

Authors: Liang Chen, Yan-Yan Tan, Zhi-Xin Chen, Tan Wang, Shu Hu, Zi-Ang Nan, Li-Qiang Xie, Yong Hui, Jing-Xin Huang, Chao Zhan, Su-Heng Wang, Jian-Zhang Zhou, Jia-Wei Yan, Bing-Wei Mao, and Zhongqun Tian

Abstract:

Perovskite solar cells are strong competitor for silicon-based ones, but suffer from poor long-term stability for which the intrinsic stability of perovskite materials is of primary concern. Herein, we prepared a series of well-defined cesium-containing mixed cations and mixed halides perovskite single crystal alloys, which enabled systematic investigations on their structural stabilities against light, heat, water and oxygen. Two potential phase separation processes are evidenced for the alloys as cesium content increases to 10% and/or bromide to 15%. Eventually, a highly stable new composition, (FAPbI3)0.9(MAPbBr3)0.05(CsPbBr3)0.05 emerges with carrier lifetime of 16 μs. It maintains stable during at least 10,000 h water-oxygen and 1,000 h light stability tests, which is very promising for long-term stable devices with high efficiency. The mechanism for the enhanced stability is elucidated through detailed single crystal structure analysis. Our work provides a single crystal-based paradigm for stability investigation, leading to discovery of stable new perovskite materials.

Full-Link: https://pubs.acs.org/doi/10.1021/jacs.8b11610