PbCl2-tuned inorganic cubic CsPbBr3(Cl) perovskite solar cells with enhanced electron lifetime, diffusion length and photovoltaic performance

Abstract Inorganic CsPbBr 3 perovskite is arousing great interest following after organic-inorganic hybrid halide perovskites, and is found as a good candidate for photovoltaic devices for its prominent photoelectric property and stability. Herein, we for the first time report on PbCl 2 -tuned inorganic Cl-doped CsPbBr 3 (Cl) perovskite solar cells with adjustable crystal structure and Cl doping for enhanced carrier lifetime, extraction rate and photovoltaic performance. The effect of PbCl 2 on the morphologies, structures, optical, and photovoltaic performance of CsPbBr 3 perovskite solar cells is investigated systemically. Compared with orthorhombic CsPbBr 3 , cubic CsPbBr 3 demonstrates a significant improvement for electron lifetime (from 6.7 ns to 12.3 ns) and diffusion length (from 69 nm to 197 nm), as well as the enhanced electron extraction rate from CsPbBr 3 to TiO 2 . More importantly, Cl doping benefits the further enhancement of carrier lifetime (14.3 ns) and diffusion length (208 nm). The Cl doped cubic CsPbBr 3 (Cl) perovskite solar cell exhibits a J sc of 8.47 mA cm −2 and a PCE of 6.21%, superior to that of pure orthorhombic CsPbBr 3 (6.22 mA cm −2 and 3.78%). The improvement of photovoltaic performance can be attributed to enhanced carrier lifetime, diffusion length and extraction rates, as well as suppressed nonradiative recombination.