Delafossite–CuFeO2 thin films prepared by atmospheric pressure plasma annealing

Abstract This study reports the use of atmospheric pressure plasma annealing to prepare the delafossite–CuFeO2 thin films. The pure delafossite–CuFeO2 phase was formed using atmospheric pressure plasma annealing at 5% O2, which had a large agglomerate morphology. The Cu-2p3/2 and the Fe-2p3/2 photoelectron peaks in the delafossite–CuFeO2 thin films were centered at 932.8 eV and 710.2 eV, indicating the chemical state of Cu and Fe were +1 and +3. The delafossite–CuFeO2 thin films had an optical bandgap of 3.1 eV. The electrical conductivity of the thin films was 0.67±0.02 S cm−1 with the carrier concentration of (2.56±1.24)×1018 cm−3. Hence, an atmospheric pressure plasma annealing offers an effective tool and a feasible method for preparing the delafossite–CuFeO2 thin films.