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 (CsPbBr3) perovskite solar cells have attracted enormous attention owing to their outstanding stability in comparison with organic-inorganic hybrid devices. The greatest weakness for inorganic CsPbBr3 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+) = La3+, Ce3+, Nd3+, Sm3+, Eu3+, Gd3+, Tb3+, Ho3+, Er3+, Yb3+, and Lu3+) into CsPbBr3 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 CsPbBr3 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 degrees C over 60 d provide new opportunities of promoting commercialization of all-inorganic CsPbBr3 perovskite solar cells.