Sub-1.4eV bandgap inorganic perovskite solar cells with long-term stability
Mingyu Hu, Min Chen, Peijun Guo, Hua Zhou, Junjing Deng, Yudong Yao, Yi Jiang, Jue Gong, Zhenghong Dai, Yunxuan Zhou, Feng Qian, Xiaoyu Chong, Jing Feng, Richard D. Schaller, Kai Zhu, Nitin P. Padture, Yuanyuan Zhou, Yuanyuan Zhou, Yuanyuan Zhou
Abstract
Abstract State-of-the-art halide perovskite solar cells have bandgaps larger than 1.45 eV, which restricts their potential for realizing the Shockley-Queisser limit. Previous search for low-bandgap (1.2 to 1.4 eV) halide perovskites has resulted in several candidates, but all are hybrid organic-inorganic compositions, raising potential concern regarding device stability. Here we show the promise of an inorganic low-bandgap (1.38 eV) CsPb 0.6 Sn 0.4 I 3 perovskite stabilized via interface functionalization. Device efficiency up to 13.37% is demonstrated. The device shows high operational stability under one-sun-intensity illumination, with T 80 and T 70 lifetimes of 653 h and 1045 h, respectively ( T 80 and T 70 represent efficiency decays to 80% and 70% of the initial value, respectively), and long-term shelf stability under nitrogen atmosphere. Controlled exposure of the device to ambient atmosphere during a long-term (1000 h) test does not degrade the efficiency. These findings point to a promising direction for achieving low-bandgap perovskite solar cells with high stability.