Optical, electrical, and structural properties of Fe-doped CuAlO2 thin films

Abstract

The influence of Fe content on the structural and optoelectronic properties of Fe-doped CuAlO2 films was studied. X-ray diffraction (XRD) results revealed that all annealed films had a pure delafossite phase. Optical transmittance spectra showed that Fe-doped films exhibit an obvious change in the 340–380[Formula: see text]nm region compared to undoped CuAlO2, and optical band gap analyses confirmed the formation of impurity band levels within the bandgap. The average transmittance of CuAl[Formula: see text]FexO2 is around 45–55% in the visible range, and transmittance in this region decreases with increasing Fe concentration. Increased conductivity was observed due to the introduction of Fe and subsequent carrier concentration enhancement. The conductivity in a CuAl[Formula: see text]Fe[Formula: see text]O2 film was maximized at [Formula: see text][Formula: see text]S[Formula: see text]cm[Formula: see text].