Thermodynamically Stable Orthorhombic γ-CsPbI 3 Thin Films for High-Performance Photovoltaics - Zhao, Boya; Jin, Shi-Feng; Huang, Sheng; Liu, Ning; Ma, Jing-Yuan; Xue, Ding-Jiang; Han, Qiwei; Ding, Jie; Ge, Qian-Qing; Feng, Yaqing; Hu, Jin-Song (Journal of the American Chemical Society, 2018)