Quasi-epitaxial growth of thick CuInS_2 films by RF reactive sputtering with a thin epilayer buffer

摘要

We demonstrate the deposition of CuInS_2 films on single-crystalline (0 0 0 1)-sapphire by radio frequency reactive sputtering with a Cu-In alloy target and H_2S gas. X-ray diffraction (XRD) revealed that the as-sputtered films are of mainly (1 1 2)-oriented CuInS_2 incorporating a minor CuIn_2 phase. XRD rocking curve of CuInS_2 (1 1 2) showed a full width at half maximum of 0.1°, indicating an epitaxial-like growth of (1 1 2)-CuInS_2 films on (0 0 0 1)-sapphire. Six peaks dominantly show up in the XRD φ-2θ map, between which there are additional regular modulations present, suggesting a multi-domain structure of the thick double-layered films. Furthermore, the morphology and internal microstructure of the quasi-epitaxially sputtered CuInS_2 films were characterized by scanning electron microscopy and transmission electron microscopy, respectively.