Growth and characterization of Sc2O3 doped Ta2O5 thin films

Appl Opt. 2020 Feb 10;59(5):A106-A111. doi: 10.1364/AO.59.00A106.

Abstract

We present the optical and structural characterization of films of Ta2O5, Sc2O3, and Sc2O3 doped Ta2O5 with a cation ratio around 0.1 grown by reactive sputtering. The addition of Sc2O3 as a dopant induces the formation of tantalum suboxide due to the "oxygen getter" property of scandium. The presence of tantalum suboxide greatly affects the optical properties of the coating, resulting in higher absorption loss at λ=1064nm. The refractive index and optical band gap of the mixed film do not correspond to those of a mixture of Ta2O5 and Sc2O3, given the profound structural modifications induced by the dopant.