Surface Passivation and Energetic Modification Suppress Nonradiative Recombination in Perovskite Solar Cells

Highlights The partial substitution of Br− on I-sites, and the restricted motion of MA + cations in correlation with suppressed electron-phonon coupling promote charge transport. The perovskite parent lattice of 2FEABr-treated perovskites was firmed, and the difficulty degree for A-site MA + cations running out of the inorganic framework was thus enhanced. The efficiency was enhanced from 19.44% to 21.06%, accompanied with excellent stability.