Structural, optical and photoluminescence properties of TiO2 and TiO2: Tm3+ nanopowders

• Published in: Optik (Stuttgart) 2021-02, Vol.227, p.166083, Article 166083
• Main Authors: Borrego-Pérez, J.A., González, Federico, Meza-Avendaño, C.A., De Los Santos, I. Montoya, López-Juárez, Rigoberto, Hernández, I., Alonso-Guzman, E.M., Martinez-Molina, W., Chavez-Garcia, H.L.
• Format: Article
• Language: English
• Subjects: (A) TiO2; (B) sol-gel growth; (D) chemical shift model; (D) optical properties; (D) Tm3+-luminescence
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2020.166083

•Modification on structural anatase structure with low thulium doping percentage.•Presence of thulium phases with anatase obtained at 500 °C.•Well-defined Tm3+f-f transition bands obtained in optical and photoluminescence characterization.•TiO2: Tm3+ chemical shift model approach. Tm3+-doped TiO2 nanocrystalline powders (in the range from 0.0 to 6 at. % of Tm3+) were synthesized by the sol-gel method at 500 °C. Structural, optical and photoluminescence properties were characterized by X-ray diffraction, transmission and scanning electron microscopy (TEM, SEM), UV–vis spectroscopy and photoluminescence spectroscopy. From XRD results all compositions show anatase structure, and the incorporation of Tm3+ promoted an increase in lattice parameters and inhibit the crystal growth. HRTEM micrographs show the presence of d-plane spacings corresponding to Tm2O3 and Tm2Ti2O7 phases for samples annealed at 500 °C. FTIR, reflectance UV–vis and photoluminescent spectra showed well defined bands ascribed to the Tm3+f-f transition. Vacuum referred binding energy diagram and chemical shift model approach are presented to analyze the relationship between the TiO2 electronic structure and the Tm3+f-f transition.