Electrical and optical properties of DC reactive magnetron sputtered CuNiO2 films: Effect of annealing temperature

Copper nickel oxide (CuNiO2) thin films were deposited onto unheated glass substrates by DC reactive magnetron sputtering the composite target of Cu50Ni50 at a fixed oxygen partial pressure of 3x10(-4) mbar and sputter pressure of 3x10(-2) mbar. The as-deposited copper nickel oxide films were annealed in air at temperatures in the range 200-300 degrees C for one hour. The as-deposited and annealed films were characterized for their chemical composition, structure, electrical and optical properties. The as-deposited films were amorphous in nature. The films annealed in air at 250 degrees C and above were polycrystalline CuNiO2. The electrical resistivity of the films increased with annealing temperature due to the filling of oxygen ion vacancies. The films annealed at 300 degrees C exhibited the crystallite size of 65 nm, electrical resistivity of 65 Omega m and optical band gap of 2.06 eV. (C) 20 17 Elsevier Ltd. All rights reserved.