Dual-Source Defect Managing of Tin–Lead Perovskite for Efficient All-Perovskite Tandem Solar Cells

All-perovskite tandem solar cells (TSCs) hold a great promise to break the Shockley-Queisser (S-Q) efficiency limit of single-junction solar cells. However, the inferior performance of the tin-lead (Sn–Pb) mixed perovskites based narrow-bandgap bottom subcells largely limits the development of all-perovskite TSCs due to the serious defects assisted non-radiative charge recombination loss, especially at the perovskite/electron charge transport layer (ETL) interface. Herein, a dual-source defect managing strategy is demonstrated to modify the top surface of Sn–Pb mixed perovskites. Specifically, ethylenediammonium diiodide (EDAI 2 ) and (3-mercaptopropyl) trimethoxysilane (MPTS) are simultaneously introduced to passivate the organic cations and metal cations related defects, respectively. The strong interactions between the passivators and Sn–Pb perovskite result in effectively reduced non-radiative carrier recombination, obviously suppressed Sn 2+ oxidation and accelerated carrier transportation at the perovskite/ETL interface. Ultimately, a champion efficiency of 22.7% for single-junction Sn–Pb solar cells and an impressive efficiency of 28.26% for the all-perovskite TSCs are achieved based on the dual-source defect managing strategy.