Effect of Nb-Content on Properties of Nb-Doped TiO₂ Films Grown by Magnetron Sputtering

The Nb-doped TiO₂ (NTO) transparent conductive thin films were deposited by RF/DC magnetron co-sputtering of TiO₂, Nb₂O₅ and Ti targets.The Influence of the Nb-content on the microstructures and properties of the Nb-doped TiO₂ coatings was investigated with X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy.The results show that the Nb-content has a major impact.To be specific, as the Nb-content increased, the resistivity of the n-type NTO coatings was found to change in a decrease-increase manner and an increasingly big blue-shift of the absorption edge was observed.Synthesized at a sputtering power of 40 W of Nb-target, the lowest resistivity was 7.3×10^-4Ω·cm and the transmittance in visible light range was over 86%.We concluded that the optimized Nb-content may result in better crystallinity and larger carrier mobility.