Effects of Substrate Temperature on Properties of Transparent Conductive Ta-Doped TiO2 Films Deposited by Radio-Frequency Magnetron Sputtering**Supported by the National Natural Science Foundation of China under Grant No 11374114.

Abstract

Ta-doped titanium dioxide films are deposited on fused quartz substrates using the rf magnetron sputtering technique at different substrate temperatures. After post-annealing at 550°C in a vacuum, all the films are crystallized into the polycrystalline anatase TiO2 structure. The effects of substrate temperature from room temperature up to 350°C on the structure, morphology, and photoelectric properties of Ta-doped titanium dioxide films are analyzed. The average transmittance in the visible region (400–800 nm) of all films is more than 73%. The resistivity decreases firstly and then increases moderately with the increasing substrate temperature. The polycrystalline film deposited at 150°C exhibits a lowest resistivity of 7.7 × 10−4 Ω·cm with the highest carrier density of 1.1 × 1021 cm−3 and the Hall mobility of 7.4 cm2 · V−1 s−1.