Microstructure and Optical Properties of Sm³⁺ Doped TiO₂ Thin Films by Oblique Angle Deposition

Abstract

TiO₂: 2%Sm³⁺ thin films were prepared by oblique angle deposition. X-ray diffraction (XRD), scanning electron microscope (SEM), UV-Vis-NIR spectrophotometer, fluorescence spectrophotometer was employed to characterize the structure and optical properties of TiO₂: 2%Sm³⁺ thin films. The results indicated that these thin films were with anisotropic columnar structure before and after calcination. The optical anisotropy measured by transmission difference (Tp-Ts) at 500nm was increasing from 8% to 33% with calcination. Under ultraviolet excitation (λ_ex = 330nm) and commercial 365nm UV lamp excitation, these TiO₂: Sm³⁺ thin films show intense ⁴G_5/2→ ⁶H_{5/2, 7/2, 9/2} emissions of Sm³⁺. The polarized photoluminescence was anticipated in the anisotropic thin films.

Keywords:

• TiO₂:Sm³⁺ STF
• Anistropy
• photoluminescence

Acknowledgment

This work was founded by the National Natural Science Foundation of China (No 60778026) and the Shanghai Rising-Star Program (No 07QB14006).