Fabrication of Low Resistivity Nb-doped TiO₂ Transparent Conductive Polycrystalline Films on Glass by Reactive Sputtering

Abstract

Nb-doped anatase TiO2 (TNO) polycrystalline films with excellent conductivity and transparency were successfully fabricated by reactive sputtering combined with post annealing in H2 gas. The H2 annealing of as-deposited amorphous films caused an abrupt decrease in resistivity (ρ), which was accompanied by crystallization into the anatase structure. A film deposited on an unheated glass substrate with subsequent H2 annealing at 600 °C exhibited a resistivity of 9.5×10-4 Ω cm and an average optical transmittance of ∼75% in the visible region. This ρ value is of the same order as that of epitaxial TNO films, which indicates that sputtering is a promising technique for obtaining large-area TNO films.