This letter reports a technique for increasing the carrier concentration and the conductivity of the p-type CuAlO2 through doping the material with nitrogen. The x-ray photoelectron spectroscopy and the optical band gap analyses suggested that the nitrogen atoms occupying the interstitial sites of the delafossite structure provided the p-type CuAlO2 with an impurity energy level in the energy gap. It was also found that the N-doped CuAlO2 film had its optimum conduction properties when the dopant level reached 1.1 at. %. Here, the carrier concentration was raised from 4.81×1016 in the undoped film to 2.13×1017 cm-3 in the doped film, and the corresponding film’s conductivity was increased from 3.8×10-2 to 5.4×10-2 (Ω cm)-1, as compared with the undoped CuAlO2 film.
