title: Solvent Engineering for Ambient-Air-Processed, Phase-Stable CsPbI3 in Perovskite Solar Cells.
abstract: Inorganic CsPbI3 perovskite solar cells (PSCs) owning comparable photovoltaic performance and enhanced thermal stability compared to organic-inorganic hybrid perovskites have attracted enormous interest in the past year. However, it is still a challenge to stabilize the desired black α-CsPbI3 perovskites in ambient air for photovoltaic applications. Herein, sequential solvent engineering including the addition of hydroiodic acid (HI) and subsequent isopropanol (IPA) treatment for fabricating stable and working CsPbI3 PSCs is developed, and a novel low-temperature phase-transition route from new intermediate Cs4PbI6 to stable α-CsPbI3 is also released for the first time. As such, the as-prepared PSCs give a relatively high power conversion efficiency (PCE) of 4.13% (reverse scan), and the steady-state power output of 1.88% is confirmed for the selected cell with an initial PCE of 3.13%. To the best of our knowledge, this is the first demonstration of fabricating CsPbI3 inorganic PSCs under fully open-air conditions.
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Paifeng
authors: P
authors: Luo
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Wei
authors: W
authors: Xia
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Shengwen
authors: S
authors: Zhou
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Lin
authors: L
authors: Sun
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Jigui
authors: J
authors: Cheng
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Chenxi
authors: C
authors: Xu
authors: Department of Materials Science and Engineering, Hefei University of Technology , Hefei, Anhui 230009, People's Republic of China.
authors: Yingwei
authors: Y
authors: Lu