Gas-medium annealing for perovskite solar cells with state-of-the-art energy loss

Abstract

The energy loss of most perovskite solar cells (PSCs) is over 0.35 eV, which is much higher than those for GaAs solar cells (0.3 eV). One of the key issues is the trade-off between perovskite crystallization and surface passivation processes. Herein, we report a single step of gas-medium annealing, which simultaneously achieves perovskite crystallization and surface passivation. The manufacturing process of PSCs was simplified and different types of defects were significantly reduced from bulk perovskites to the surface. The corresponding device exhibited a certified efficiency of 26.1% (certified V_OC of 1.21 V) with an unprecedentedly small energy loss of 0.29 eV. The devices were highly reproducible and the encapsulated devices exhibited high stability following ISOS-D-2 and ISOS-L-1 protocols.