All-inorganic metal-halide CsPbBr perovskite has emerged as an attractive photovoltaic material for its outstanding environmental stability. However, due to the wide bandgap, the performance of CsPbBr perovskite solar cells (PSCs) is limited, especially for the short-circuit current density (J). In this issue of Energy & Environmental Materials, Guo et al. employed Nb-doped SnO as electron transporting layers (ETLs), which could greatly improve the J of the PSCs based on all-inorganic CsPbBr3.