Structural properties of epitaxial CuInS2 films on Si and CaF2 substrates

Using molecular beam epitaxy (MBE), we have been able to produce epitaxial CuInS2 layers on S-terminated Si(111) surfaces. During a layer-by-layer deposition, we investigate the growth process by means of the in situ, methods low energy electron diffraction (LEED) and Auger electron spectroscopy (AES). The data indicate the first cation layers to be disordered, while the chalcopyrite order prevails for thicker films. This is confirmed by means of transmission electron microscopy (TEM), which also reveal misfit dislocations and twinning as typical features of the CuInS2 layers. The CuInS2 layers on Si are compared to the first epitaxially grown CuInS2 films on CaF2 substrates of (111) orientation.