Bifunctional Stabilization of All-Inorganic α-CsPbI3 Perovskite for 17% Efficiency Photovoltaics

• DOI: 10.1021/jacs.8b07927
• Publication Date: 2018-09-24T12:55:09Z
• Authors: Yong Wang; Taiyang Zhang; Miao Kan; Yixin Zhao
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

The all-inorganic α-CsPbI3 perovskite with the most suitable band gap faces serious challenges of low phase stability and high moisture sensitivity. We discover that a simple phenyltrimethylammonium bromide (PTABr) post-treatment could achieve a bifunctional stabilization including both gradient Br doping (or alloying) and surface passivation. The PTABr treatment on CsPbI3 only induces less than 5 nm blue shift in UV-vis absorbance but significantly stabilize the perovskite phase with much better stability. Finally, the highly stable PTABr treated CsPbI3 based perovskite solar cells exhibit a reproducible photovoltaic performance with a champion efficiency up to 17.06% and stable output of 16.3%. Therefore, this one-step bifunctional stabilization of perovskite through gradient halide doping and surface organic cation passivation presents a novel and promising strategy to design stable and high performance all-inorganic lead halide.