Structural and optical properties of γ-ray irradiated TiO2 single crystals

Abstract The effects of γ-ray irradiation on structural and optical properties of TiO2 were investigated. γ-ray irradiation was skillfully used to induce oxygen vacancy (VO) in rutile TiO2. Photoluminescence (PL) and Electron Spin-Resonance (ESR) methods employed to characterize VO defects. Optical properties characterized by UV–Vis spectra, the optical bandgap decreased with the increase in irradiation dose. To verify this phenomenon, the CASTEP module was used to calculate the microstructural and optical properties of VO, 2VO, and 3VO in rutile TiO2. VO could induce defects state and new defects levels, which decrease the bandgap and expand the absorption in visible light. Theoretical results agree well with the experimental data.