Fig. 1: Structural characterizations of the CsPbClBr2 nanocrystal films.

a Schematic illustration of the in situ fabrication process for CsPbClBr2 nanocrystal films. b The integrated intensity-q relations of GIWAXS patterns for the CsPbClBr2 nanocrystal films with different ratios between DPPABr and PEABr. Inset: partial enlarged intensity-q curves (0.45–2.5 Å−1). c Schematic diagram of QWD for DPPABr-only and PEABr-only CsPbClBr2 nanocrystal films.