Structure and optoelectrical properties of transparent conductive MGZO films deposited by magnetron sputtering

The transparent conductive Mg-Ga co-doped ZnO (MGZO) films were prepared by radio-frequency (RF) magnetron sputtering. The influence of substrate temperature on the structural and optoelectrical properties of the films is studied. The results show that all the films possess a preferential orientation along the (002) plane. With the increase of substrate temperature, the structure and optoelectrical properties of the films can be changed. When substrate temperature is 300 °C, the deposited film exhibits the best crystalline quality and optoelectrical properties, with the minimum micro strain of 1.09×10 -3 , the highest average visible transmittance of 82.42%, the lowest resistivity of 1.62×10 -3 Ω·cm and the highest figure of merit of 3.18×10 3 Ω -1 ·cm -1 . The optical bandgaps of the films are observed to be in the range of 3.342—3.545 eV. The refractive index dispersion curves obey the Sellmeier’s dispersion model.