Fig. 1

Structural characterization of Cs₄PbBr₆ NCs. a TEM image and the corresponding size distribution of as-prepared Cs₄PbBr₆ NCs with Gauss fitting, given in the inset. b High-resolution TEM (HRTEM) image of Cs₄PbBr₆ NCs before compression. Scale bars are 100 nm in the TEM image and 10 nm in the HRTEM image. c HAADF-STEM image and elemental mapping (Cs, Pb, and Br) of the as-prepared Cs₄PbBr₆ NCs (scale bar is 50 nm). Schematic crystal structure of Cs₄PbBr₆ along (d) and perpendicular (e) to (001)