Credit:
Left: Schematic of spin coating process used to produce epitaxial films and nanocrystals, image by Meagan V. Kelso. Right: Electron and optical microscope images of epitaxial (A) cesium lead bromide, (B) lead iodide, (C) sodium chloride and (D) zinc oxide, from Science 2019 DOI: 10.1126/science.aaw6184.