Fig. 4: Morphological and crystal orientation characterizations.

a, b Top-view SEM images, c, d 2D GIWAXS data and e, f tube integrals at qxy ≈ −1Ǻ−1 obtained from the 2D GIWAXS data of the pristine MAPbI3 and champion films. The insets in a, b are the corresponding cross-sectional SEM images