Morphological and optical characteristics of nanocrystalline TiO₂thin films by quantitative optical anisotropy and imaging techniques

Abstract

TiO2 thin films were prepared by dc reactive sputtering with different ratios of oxygen to argon. The optical characteristics of the films were studied by birefringence imaging and optical anisotropic analysis using MetriPol. A clear trend of aggregation and structural variation of TiO2 nanoparticles in the films can be seen using MetriPol optical anisotropic imaging. It was found that the optical characteristics of the TiO2 thin films depend on the ratios of O2/Ar during sputtering of the films. The optical anisotropies are closely related to the structural feature of TiO2 nanoparticles. Variation trends of TiO2 film structures and optical characters have also been confirmed by FESEM observations and refractive index.