Epitaxial growth and X-ray diffraction analysis of single-crystal thin films of CuCl

The epitaxial growth of single-crystal thin films of cuprous chloride (CuCl) with 2 to 4-μm thicknesses is reported for the first time. Single-crystal structure is achieved by thermal deposition of CuCl onto a sodium chloride (NaCl) substrate whose space lattice and lattice constant match that of CuCl. X-ray diffraction analysis reveals single-crystal structure of these CuCl thin films. Luminescence spectra arising from the decay of excitonic molecules to exciton states are substantially narrower in the single crystal thin films compared with polycrystalline thin films grown on amorphous substrates.