Investigation of properties of transparent and conducting V-doped Ga2O3 films

V-doped Ga2O3 films were prepared by using radio frequency (RF) magnetron sputtering method with different substrate temperature. The influence of substrate temperature on the properties of V-doped Ga2O3 films was investigated. The results indicated that the crystalline quality of the films increases significantly with increasing substrate temperature. All films showed a smooth surface and high visible light transmission. As the substrate temperature increased, the optical band gap of the films decreased slightly and the resistivity decreased drastically. XPS spectra revealed the valence state of V dopant in the films and two binding energies corresponding to V4+ and V5+ ions were obtained.