Fig. 3: Bending durability of flexible perovskite films.

a Top-view SEM images of the top and bottom surfaces of control perovskite film after 10000 convex bending cycles at a curvature radius of 5 mm. b,c Schematic diagram of the control (b) and target (c) perovskite films in convex and concave bending conditions. The difference at GBs during bending indicates the possible working mechanism of MeOBABr capping. d Top-view SEM images of the top and bottom surfaces of target perovskite film after 10000 concave bending cycles at a curvature radius of 5 mm.