Carrier generation mechanism and effect of tantalum-doping in transparent conductive amorphous SnO2thin films

We investigated the transport properties of amorphous undoped and Ta-doped SnO 2 thin films grown on unheated glass substrates by pulsed laser deposition. Optimized films exhibited a resistivity of 2 × 10 −3 Ω cm, carrier density ( n e ) of (1–2) × 10 20 cm −3 , and were highly transparent in the visible region. Ta-doping had little effect on n e in amorphous films, in contrast to in crystalline phases. These results suggest that carrier electrons in amorphous SnO 2 films originated from oxygen vacancies, similar to in In 2 O 3 -based amorphous films.