Influence of substrate temperature on structural, electrical, and optical properties of transparent conductive hydrogen and vanadium co-doped ZnO films fabricated by radiofrequency magnetron sputtering

In this study, we fabricate hydrogen and vanadium co-doped ZnO (HVZO) films using radio frequency magnetron sputtering from a ceramic target with various substrate temperatures (STs) at a fixed H2 flow rate. The results reveal that the HVZO films exhibit a (002) preferred orientation with the c-axis perpendicular to the substrate, and the morphology changes from small and loose grains to large blocks and then to small grains. A minimum resistivity of 1.15 × 10−3 Ω cm, along with a high average transmittance greater than 80% at a wavelength of 400-1200 nm, is obtained at an ST of 150 °C. We apply theoretical calculations based on density functional theory to analyze the electronic structure and conduction mechanism. The configuration of HVZO-1, where the optical band gap is widening and the charge carrier predominantly originates from the orbits of V 3d, O 2p, and H 1s, is found to be the most stable.