Characterization of CuAlO2 thin film prepared by rapid thermal annealing of an Al2O3/Cu2O/sapphire structure

CuAlO2 thin film was successfully prepared by rapid thermal annealing of an Al2O3/Cu2O/sapphire structure in air above 1000 °C. The film was mostly with single crystalline structure as verified by X-ray diffraction methods. We found that crystal quality and electrical conductivity of the films were affected by the cooling rate after annealing. The highest conductivity obtained in this work was 0.57 S/cm. Optical gap of this film was determined to be 3.75 eV.