The influence of growth temperature and oxygen on the phase compositions of CuAlO2 thin films prepared by pulsed laser deposition

Single-phase CuAlO2 thin films with (0 0 l) orientation were prepared by PLD with ex situ annealing at 1173 K under N2 atmosphere. The phase compositions of the films were found to be significantly dependent on the deposition oxygen pressure. The optimum deposition oxygen pressure for single-phase CuAlO2 thin films was 2.3–3.2 × 10−2 Pa. The average transmittance of the ∼50 nm-thick film in the visible region is ∼60% and the direct optical band gap is ∼3.43 eV. The single-phase film has a resistivity of 99.2 Ω cm at 300 K.