Enhanced crystallization in the CsPbBr3 all-inorganic perovskite via an advanced nucleation method

Abstract

Organic–inorganic hybrid halide perovskites are unstable under ultraviolet (UV) irradiation. To solve this profound issue, an all-inorganic CsPbBr₃ perovskite device is used as the top cell to overcome the ultraviolet light instability of the FAPbI₃ photovoltaic device (bottom cell). The inorganic CsPbBr₃ layer is prepared via an advanced nucleation process to decrease the Gibbs free energy, resulting in more nuclei as well as a dense layer. The prepared CsPbBr₃ layer acts as a UV filter to avoid the problem of UV light instability on the bottom cell. When the dense CsPbBr₃ layer acts as a top cell in the 4-terminal tandem device, the FAPbI₃ based bottom cell exhibits excellent stability during the UV test.