Carrier generation mechanism and effect of tantalum-doping in transparent conductive amorphous SnO2 thin films

Abstract

We investigated the transport properties of amorphous undoped and Ta-doped SnO2 thin films grown on unheated glass substrates by pulsed laser deposition. Optimized films exhibited a resistivity of 2 × 10−3 Ω cm, carrier density (ne) of (1–2) × 1020 cm−3, and were highly transparent in the visible region. Ta-doping had little effect on ne in amorphous films, in contrast to in crystalline phases. These results suggest that carrier electrons in amorphous SnO2 films originated from oxygen vacancies, similar to in In2O3-based amorphous films.