Structural, electrical and optical properties of epitaxial Ta-doped titania films by MOCVD

Abstract

This work presented a detailed study on epitaxial Ta-doped titania (TiO₂:Ta) films deposited via a metal organic chemical vapor deposition method. The effects of Ta dopant concentration on the film microstructure and functional characteristics including electrical and optical properties were systematically explored. The results indicated the deposited TiO₂:Ta films exhibit high crystallization quality, good transparency (>92%) in the visible range, and tunable electrical properties. The maximum carrier mobility (15.4 cm² V⁻¹ s⁻¹) and minimum resistivity (8.2 × 10⁻² Ω cm) were achieved at Ta concentrations of 1.0% and 4.0%, respectively. The optical band gaps of the deposited films increased from 3.48 to 3.57 eV with the increase of Ta concentration from 0 to 8.0%.