Ion migration suppression mechanism via 4-sulfobenzoic acid monopotassium salt for 22.7% stable perovskite solar cells

The deep-level traps at grain boundaries (GBs) and halide ion migration are quite challenging for further enhancement of the stability efficiency perovskite solar cells (PSCs) as well elimination notorious hysteresis. Herein, we report a large-sized strongly coordinated organic anion GB anchoring strategy suppressing passivating defects in planar PSCs. practical implementation this involves incorporation potassium salts containing counter (4-sulfobenzoic acid monopotassium salt, SAMS) into precursor. It has been found that anions within SAMS can be firmly anchored GBs due to strong coordination interaction between C=O and/or S=O both ends bulky undercoordinated Pb2+ vacancies, along with hydrogen bond −OH formamidinium. not only passivate shallow-level but also cause more effective passivation defects. manipulation results reduced defect density, an increased carrier lifetime suppressed migration, which turn contributed enhanced PSCs together thorough As result, SAMS-modified device outstanding fill factor 0.84 delivers significant improvement (22.7%) comparison control (20.3%). unencapsulated modified demonstrates little degradation after 1320 h 60°C.