Rubidium fluoride additive for high-efficiency and low-hysteresis all-inorganic CsPbI₃ perovskite solar cells

Abstract

All-inorganic CsPbI3 perovskite solar cells (PSCs) technology is gradually maturing. However, the power conversion efficiency still needs to be improved, and the hysteresis phenomenon seriously hinders the development of PSCs. Herein, in this paper, a new inorganic fluorine-containing additive was developed, rubidium fluoride (RbF) was used as a precursor additive, and the incorporation of RbF effectively improved the crystallization kinetics of CsPbI3 perovskite films and inhibited the occurrence of hysteresis. The experimental results doped 0.03 mol% RbF in CsPbI3 effectively inhibited the formation of perovskite layer defects and promoted the carrier dynamics process. The non-radiative recombination is significantly suppressed, and the device stability is significantly improved. In particular, by doping 0.03 mol% RbF into the CsPbI3, the hysteresis index of PSCs is 0.003. The RbF doping of 0.03mol% in CsPbI3 effectively improves the PCE of PSCs, and the highest efficiency can reach 17.21%. The environmental stability of the RbF doping of 0.03mol% has also been significantly enhanced.