(a) In situ GIWAXS analysis showing the dynamic transformation from Pb(Ac)2 : MAI precursors in the DMI solvent to perovskite. (b) 2D GIWAXS for the thermally annealed perovskite films. (c–h) SEM images of perovskite films blade-coated at different processing temperatures ranging from 130°C to 230°C. (i) Processing temperature-dependent crystalline features of perovskite films. (j) The influences of processing temperature (fixed speed of 1.5 m/min) and coating speed (fixed temperature of 210°C) on film thickness.