Low-Temperature Aging Provides 22 E cient Bromine-Free and Passivation Layer-Free Planar Perovskite Solar Cells

摘要

cqvip:Previous reports of formamidinium/methylamine(FAMA)-mixed halide perovskite solar cells have focused mainly on controlling the morphology of the perovskite film and its interface—for example,through the inclusion of bromine and surface passivation.In this paper,we describe a new processing pathway for the growth of a high-quality bromine-free FAMAPbI3 halide perovskites via the control of intermediate phase.Through low-temperature aging growth(LTAG)of a freshly deposited perovskite film,α-phase perovskites can be seeded in the intermediate phase and,at the same time,prevent beta-phase perovskite to nucleate.After postannealing,large grain-size perovskites with significantly reduced PbI2 presence on the surface can be obtained,thereby eliminating the need of additional surface passivation step.Our pristine LTAG-treated solar cells could provide PCEs of greater than 22%without elaborate use of bromine or an additional passivation layer.More importantly,when using this LTAG process,the growth of the pure alpha-phase FAMAPbI3 was highly reproducible.