Effect of substrate temperature on the structural, electrical, and optical properties of GZO/ZnO films deposited by radio frequency magnetron sputtering

Ga-doped ZnO (GZO)/ZnO bi-layered films were deposited on glass substrates by radio frequency magnetron sputtering at different substrate temperatures of 100, 200 and 300 °C to investigate the effects of substrate temperature on the structural, electrical, and optical properties of the films. Thicknesses of the GZO and ZnO buffer layer were kept constant at 85 and 15 nm by controlling the deposition times. The films deposited at room temperature had a relatively low optical transmittance of 80.5%, while films deposited at substrate temperature of 300 °C showed a higher transmittance of 84.5% compared to the other films. Electrical resistivity of the films was also influenced by substrate temperature and the lowest resistivity of 2.7×10−3 Ω cm was observed for films deposited at 300 °C. The observed result means that increasing the substrate temperature enhanced the optical transmittance and electrical conductivity of GZO/ZnO bi-layered films, simultaneously.