Implementing Dopant-Free Hole-Transporting Layers and Metal-Incorporated CsPbI(2)Br for Stable All-Inorganic Perovskite Solar Cells

[Image: see text] Mixed-halide CsPbI(2)Br perovskite is promising for efficient and thermally stable all-inorganic solar cells; however, the use of conventional antisolvent methods and additives-based hole-transporting layers (HTLs) currently hampers progress. Here, we have employed hot-air-assisted perovskite deposition in ambient condition to obtain high-quality photoactive CsPbI(2)Br perovskite films and have extended stable device operation using metal cation doping and dopant-free hole-transporting materials. Density functional theory calculations are used to study the structural and optoelectronic properties of the CsPbI(2)Br perovskite when it is doped with metal cations Eu(2+) and In(3+). We experimentally incorporated Eu(2+) and In(3+) metal ions into CsPbI(2)Br films and applied dopant-free copper(I) thiocyanate (CuSCN) and poly(3-hexylthiophene) (P3HT)-based materials as low-cost hole transporting layers, leading to record-high power conversion efficiencies of 15.27% and 15.69%, respectively, and a retention of >95% of the initial efficiency over 1600 h at 85 °C thermal stress.