Structural and physical properties of Mg-doped CuAlO2 thin films

The CuAl1−xMgxO2 (x = 0, 0.01, 0.02 and 0.05) thin films were successfully deposited on quartz substrate by using the RF magnetron sputtering technique. XRD patterns indicate that the delafossite structure could be guaranteed for all CuAl1−xMgxO2 films. The conductivity measured at room temperature for CuAl0.98Mg0.02O2 film is three orders of magnitude higher than that of undoped CuAlO2 film and the band gaps of CuAl1−xMgxO2 (x = 0, 0.01, 0.02 and 0.05) thin films decrease with the increase of the doping concentration, which is related to the formation of impurity energy levels with increasing the doping concentration.