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

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.