Tungsten–tellurite glasses and thin films doped with rare-earth elements produced by radio frequency magnetron deposition

The formation of tungsten–tellurite films and investigation of their Raman scattering properties, and the studding of the luminescence properties of tungsten–tellurite glasses doped with Er3+ were performed. The amorphous tungsten–tellurite films were deposited by reactive radio frequency magnetron sputtering. For Raman measurements the samples of TeO2–WO3 films without Er3+ doping were prepared. Raman spectra of the tungsten–tellurite films of the composition (100-x) TeO2–xWO3 with x = 5–30 mol% were measured. Raman measurements demonstrated that tellurium save the coordination of four in the films, corresponding to the coordination in the bulk glasses and had a short range order like the one in the crystalline α-TeO2.For measuring of optical absorption and photoluminescence spectra the Er3+-doped TeO2–WO3 glass samples were used. The maximum of photoluminescence spectra was observed in the Er-doped TeO2–WO3 glasses and films at the wavelength of ~ 1.53 μm. The Judd–Ofelt parameters, Ωλ (λ = 2, 4, 6), of Er3+ are evaluated from optical absorption spectra for tungsten–tellurite glasses. Er3+-doped tungsten–tellurite glasses showed very high quantum efficiency when comparing the calculated radiative decay time with the measured lifetime of the 4I13/2 metastable level. The estimation of Judd–Ofelt parameters gave the values of Ω2 = (4.28 ± 0.2) × 10− 20 cm2, Ω4 = (1.13 ± 0.2) × 10− 20 cm2 and Ω6 = (0.72 ± 0.2) × 10− 20 cm2, which were in good agreement with data published in literature for other tungsten–tellurite glasses.