Synthesis of Cu3SbS4, Cu3SbSe4 and CuSbTe2 thin films via chalcogenation of sputtered Cu-Sb metal precursors

Cu-Sb-X (X = S, Se, Te) based ternary chalcogenide semiconductors are potential candidates for photovoltaic and thermoelectric applications. We report the synthesis of Cu3SbS4, Cu3SbSe4 and CuSbTe2 thin films by a two-stage process. The thin films were prepared by the deposition of Cu and Sb precursors on to a sapphire substrate by radio frequency magnetron co-sputtering followed by a subsequent chalcogenation process. The crystallinity, compositional, morphological and optical properties of the synthesized samples were investigated by x-ray diffraction, elemental analyses, scanning electron microscopy, optical spectroscopy and Raman spectroscopy. The Raman spectra of the synthesized Cu3SbS4, Cu3SbSe4 and CuSbTe2 samples show dominant modes at 319 cm-1, 184 cm-1, and 114 cm-1, and the band edges estimated from the transmittance and reflectance spectra, are 1.0 eV, 0.8 eV, and 0.7 eV, respectively.