Zhang Taiyang, Dar M Ibrahim, Li Ge, Xu Feng, Guo Nanjie, Grätzel Michael, Zhao Yixin
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China.
Laboratory of Photonics and Interfaces, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Sci Adv. 2017 Sep 29;3(9):e1700841. doi: 10.1126/sciadv.1700841. eCollection 2017 Sep.
Among various all-inorganic halide perovskites exhibiting better stability than organic-inorganic halide perovskites, α-CsPbI with the most suitable band gap for tandem solar cell application faces an issue of phase instability under ambient conditions. We discovered that a small amount of two-dimensional (2D) EDAPbI perovskite containing the ethylenediamine (EDA) cation stabilizes the α-CsPbI to avoid the undesirable formation of the nonperovskite δ phase. Moreover, not only the 2D perovskite of EDAPbI facilitate the formation of α-CsPbI perovskite films exhibiting high phase stability at room temperature for months and at 100°C for >150 hours but also the α-CsPbI perovskite solar cells (PSCs) display highly reproducible efficiency of 11.8%, a record for all-inorganic lead halide PSCs. Therefore, using the bication EDA presents a novel and promising strategy to design all-inorganic lead halide PSCs with high performance and reliability.
在各种比有机-无机卤化物钙钛矿具有更好稳定性的全无机卤化物钙钛矿中，具有最适合串联太阳能电池应用带隙的α-CsPbI在环境条件下面临相不稳定问题。我们发现，少量含有乙二胺（EDA）阳离子的二维（2D）EDAPbI钙钛矿可稳定α-CsPbI，避免形成不良的非钙钛矿δ相。此外，EDAPbI的二维钙钛矿不仅有助于形成在室温下数月和在100°C下超过150小时都表现出高相稳定性的α-CsPbI钙钛矿薄膜，而且α-CsPbI钙钛矿太阳能电池（PSC）还显示出11.8%的高度可重复效率，这是全无机铅卤化物PSC的记录。因此，使用双阳离子EDA为设计高性能和可靠性的全无机铅卤化物PSC提供了一种新颖且有前景的策略。
