Enhancing the efficiency and longevity of inverted perovskite solar cells with antimony-doped tin oxides

Inverted perovskite solar cells possess great potential for single or multi-junction photovoltaics. However, energy and charge losses at the interfaces limit their performance. Here we introduce p-type antimony-doped tin oxides (ATO_x) combined with a self-assembled monolayer molecule as an interlayer between the perovskite and hole-transporting layers (HTL) in inverted solar cells. ATO_x increases the chemical stability of the interface; we show that the redox reaction that commonly took place at the NiO_x/perovskite interface is negligible at the ATO_x/perovskite interface. We demonstrate that ATO_x suppresses non-radiative recombination in the perovskite layer and enhances the depletion at the perovskite/HTL interface for efficient charge extraction. Owing to these combined improvements, we achieve inverted perovskite solar cells with a maximum efficiency of 25.7% (certified steady-state efficiency of 24.8%) for an area of 0.05 cm², retained under maximum power point tracking over 500 h and 24.6% (certified steady-state efficiency of 24.0%) for an area of 1 cm².