Structural, electrical, and optical properties of transparent conductive ZnO:Ga films prepared by DC reactive magnetron sputtering

Transparent conductive Ga-doped zinc oxide (ZnO:Ga) films with highly (0 0 2)-preferred orientation were deposited on glass substrates by DC reactive magnetron sputtering. Variation of structural, electrical, and optical properties with Ga content was investigated. The peak position of the (0 0 2) plane is linearly shifted to the lower 2θ value with the increase of Ga content. The lowest resistivity of the ZnO:Ga films is 3.51×10−4 Ω cm and the average transmittance of the films is over 90% in the visible range. The optical band gap of the films is in the range of 3.58–3.74 eV. The optimum growth condition was obtained by using the Zn–Ga alloy target of 3.0 at% Ga content.