Fig. 1

Schematic illustrations of in-situ cross-linked organic/perovskite films. a Chemical structure of TMTA with marked carbonyl (blue) and alkenyl (red) groups. b Cross-linking polymerization of TMTA under thermal conditions. c Working mechanism of TMTA in PSCs: TMTA chemically anchors to the grain boundaries of MAPbI3 and then in-situ cross-links to a continuous network polymer