Growth and electrical properties of epitaxial CuInS2 thin films on GaAs substrates

CuInS2 thin films with thicknesses in the range of 500 Å were deposited onto semi‐insulating (111) A‐oriented GaAs substrates by flash evaporation in the substrate temperature range Tsub = 570 … 870 K. Epitaxial growth begins at Tsub = 645 K. The films had always the chalcopyrite structure. Indications to a transition from the chalcopyrite phase to the sphalerite phase were observed at Tsub = 870 K. Films grown at Tsub ≦ 800 K showed n‐type conductivity whereas at growth temperatures Tsub ≧ 850 K the films were always p‐type conducting. A donor level and an acceptor level with ionization energies of 0.24 eV and 0.22 eV, respectively, were found from an analysis of the electrical measurements.