Simultaneous Cesium and Acetate Coalloying Improves Efficiency and Stability of FA0.85MA0.15PbI3 Perovskite Solar Cell with an Efficiency of 21.95%

• DOI: 10.1002/solr.201900220
• Publication Date: 2019-07-06T14:43:32Z
• Authors: Shihao Yuan; Yuan Cai; Shaomin Yang; Huan Zhao; Fang Qian; Yu Han; Jie Sun; Zhike Liu; Shengzhong (Frank...
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

A simple coalloying strategy is applied to improve the efficiency and stability of FA0.85MA0.15PbI3 perovskite solar cells (PSCs) by using cesium acetate (CsAc) as an additive. It is found that the simultaneous incorporation of cation (Cs+) and anion (Ac−) into the FA0.85MA0.15PbI3 film is an effective approach to realize lattice contraction, grain size enlargement, photoelectric properties improvement, band structure modulation, and therefore the optimization of the efficiency and stability of PSCs. At optimal CsAc alloying, the FA0.85MA0.15PbI3 PSCs achieve a maximum power conversion efficiency (PCE) of 21.95% and an average of over 21%. In addition, the alloyed PSCs retain 97% of their initial PCE values after aging for 55 days in air without encapsulation.