Hole-Transport Management Enables 23%-Efficient and Stable Inverted Perovskite Solar Cells with 84% Fill Factor

Highlights A graded inverted solar cell configuration is developed by hole-transport management aiming to suppress interface defects-induced non-radiative recombination for efficient hole transport. NiO x -based inverted PSCs present a power-conversion-efficiency over 23% with a high fill factor of 0.84 and open-circuit voltage of 1.162 volts, one of the best performances reported so far for 1.56-electron volt bandgap formamidinium-based triple-halide perovskites. Devices show high operational stability over 1,200 h during T 90 lifetime measurement under 1-sun illumination in ambient-air conditions.