Fabrication of TiO₂-CuInS₂ nanocomposite on ITO substrate via liquid carbon dioxide coating

Abstract TiO2-CuInS2 is one of the promising materials for 3D nanocomposite solar cells. To utilize for 3D nanocomposite solar cells, TiO2-CuInS2 should well deposited onto transparent conducting oxide such as indium doped tin oxide (ITO). High pressure coating with liquid carbondioxide (l-CO2) was successfully deposited TiO2-metals chalcogenide onto ITO substrate. Further heat treatment (oxidation and sulfurization) lead the formation of CuInS2 from metals chalcogenide deposited on the mesoporous TiO2. The formation of CuInS2 on the was confirmed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD) and Raman spectroscopy. The atomic ratios of deposited CuInS2 were nearly stoichiometric after sulfurization. The crystal growths of CuInS2 were controlled by adjusting the number of coating cycles.