Lanthanide Ions Doped CsPbBr3 Halides for HTM-Free 10.14%-Efficiency Inorganic Perovskite Solar Cell with an Ultrahigh Open-Circuit Voltage of 1.594 V

All-inorganic cesium lead bromide (CsPbBr 3 ) perovskite solar cells have attracted enormous attention owing to their outstanding stability in comparison with organic–inorganic hybrid devices. The greatest weakness for inorganic CsPbBr 3 solar cells is their lower power conversion efficiencies, mainly arising from inferior light-absorbance range and serious charge recombination at interfaces or within perovskite films. To address this issue, the lattice doping of lanthanide ions (Ln 3+ = La 3+ , Ce 3+ , Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ , Tb 3+ , Ho 3+ , Er 3+ , Yb 3+ , and Lu 3+ ) into CsPbBr 3 films for all-inorganic solar cells free of hole-transporting materials and precious metal electrodes is presented. Arising from the enlarged grain size and prolonged carrier lifetimes upon incorporating Ln 3+ ions into perovskite lattice, the performances of these inorganic CsPbBr 3 solar cell devices are significantly enhanced, achieving a champion efficiency as high as 10.14% and an ultrahigh open-circuit voltage of 1.594 V under one sun illumination. Meanwhile, the nearly unchanged efficiency upon persistent attack by 80% RH in air atmosphere over 110 d and enhanced thermal stability at 80 °C over 60 d provide new opportunities of promoting commercialization of all-inorganic CsPbBr 3 perovskite solar cells.