High Temperature Stability of Anatase Films Prepared by MOCVD

Abstract

Highly thermally stable anatase films were prepared by metal-organic chemical vapor deposition (MOCVD) using Ti(O-i-Pr)₂(dpm)₂ as precursor. The effect of heat treatment on the microstructure, transmittance, optical band gap and refractive index of anatase films was investigated. Anatase films in a single phase were obtained at T_sub (substrate temperature) < 723 K. By heat-treating the anatase film at 1273 K, no phase transformation was observed without changing the transmittance and optical band gap, whereas the refractive index increased. A small amount of rutile phase was identified in the anatase film by heat-treating at 1323 K. The anatase films transformed into rutile in a single phase by heat-treating at 1373 K, resulting in a decrease in transmittance and optical bandgap and an increase in refractive index.