Growth, Structure and Optical Properties of CuNi-Oxide Films for Nanophotonics and Photovoltaics

Abstract

Cu and Ni from CuNi metallic targets (composition 20-80 and 46-54 at.%) are deposited on Corning glass, quartz and the native oxide of Si (100) wafers by direct current magnetron sputtering in a high vacuum chamber (base pressure 5 x 10-5 mbar). The CuNi films, with thickness 40 200 nm, are post annealed at temperatures 400 - 500 °C in a furnace under atmospheric air in order to be fully oxidized. The structure of the films is studied by x-ray diffraction experiments. Phase separation of the oxides is evident. The optical properties are studied via ultraviolet-visible light absorption spectroscopy. The spectra of CuNi-oxide films are compared with the spectra of the pure CuO and NiO films. Features originating from both CuO and NiO are detected in the spectra of the CuNi-oxide thin films.