A study of optical absorption in thin amorphous Ce O₂-TeO₂ films

Abstract

Optical absorption in the wavelength range 300 to 800 nm is studied in Ce O₂-TeO₂ amorphous films prepared by a co-evaporation process. The fundamental optical absorption edge is sharp, resembling that found in crystalline rather than amorphous materials-as has been previously reported for Ce O₂-TeO₂/SiO films (Al-Dhhan and Hogarth 1986). The optical gap generally decreases as the proportion of CeO₂ in the mixed films is increased, but for the sample with less than 10wt% TeO₂ the optical gap is higher than for the CeO₂ film.