Transparent conducting zirconium-doped zinc oxide (ZnO:Zr) and aluminium-doped zinc oxide (ZnO:Al) thin films were deposited on glass substrates by direct current (DC) magnetron sputtering at room temperature. The crystallinity of ZnO:Zr and ZnO:Al thin films increases as the target-to-substrate distance decreases, and the crystallinity of ZnO:Zr films is found to be always better than that of ZnO:Al films prepared under the same deposition conditions. As the target-to-substrate distance decreases, the resistivity of both film types decreases greatly while the optical transmittance does not change much with the variation of the distance. When target-to-substrate distance is 4.1 cm, the lowest resistivity of 6.0×10-4Ω·cm and 5.7×10-4Ω·cm was obtained for ZnO:Zr and ZnO:Al films, respectively. The figure of merit arrived at a maximum value of 3.98×10-2Ω for ZnO:Zr films lower than 5×10-2Ω for ZnO:Al films.

Transparent conductive ZnO:Zr thin films with different thicknesses were fabricated on glass slides by DC reactive magnetron sputtering from Zn:Zr targets consisting of Zn disk and Zr metallic chips in Ar+O2mixture gas. X-ray diffraction, four-point probe measurements, UV–vis spectrophotometers and thin film thickness tester were employed to characterize the structure, electrical and optical properties of ZnO:Zr films, respectively. The experimental investigations indicate that film thickness has an important effect on the crystal structure, optical and electrical properties of the deposited films.

Transparent conducting Ti-Al co-doped zinc oxide films (TGZO) with high transparency and relatively low resistivity have been successfully prepared on water-cooled glass substrate by DC magnetron sputtering at room temperature. All the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. The Ar sputtering pressure was varied from 1.5 to 13 Pa. The electrical resistivity decreases when the sputtering pressure increases from 1.5 to 7.5 Pa. The electrical resistivity increases when the sputtering pressure increases from 7.5 to 13 Pa. When the sputtering pressure is 7.5 Pa, it is obtained that the lowest resistivity is 2.18×10-4Ω⋅cm. In the visible region, all the deposited films show a high average transmittance of above 92 %.