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The TeO2–TiO2–ZnO glass was single doped with Er3+ and its structural, luminescent, and upconversion properties were analyzed. The amorphous nature of the fabricated glass was confirmed by X-ray diffraction, and the characteristic vibrational modes of the tellurite-titanium-zinc glass network were identified by Raman spectroscopy. The photoluminescent and upconversion properties of Er3+ doped glass was analyzed by time decay measurements at different excitation wavelengths. The spectra recorded upon excitations at 808 nm and 975 nm show an intense green upconversion luminescence corresponding to the 2H11/2, 4S3/2 → 4I15/2 transitions and a very weak red emission associated to the 4F9/2 → 4I15/2 transition. The experimental results suggest that in Er3+ doped glass the excited state absorption and/or energy transfer mechanisms are responsible for upconversion luminescence observed upon 808 nm and 975 nm excitations.

The long persistent luminescence, thermoluminescence (TL) and IR stimulated luminescence properties of two orthorhombic strontium aluminates (Sr4Al14O25) co-doped with Eu2+, Dy3+ and Eu2+, Nd3+ exposed to beta radiation is reported. The phosphors were synthesized by the combustion method followed by a post-annealing treatment under a reductive carbon atmosphere. Photoluminescence emission spectra of both phosphors are typical for emission of Eu2+ ions with 7-fold and 10-fold coordination in Sr4Al14025 and consist of the main band at 480 nm and a weak band between 390 and 440 nm. After exposure to beta radiation the Sr4Al14025:Eu2+,Dy3+ phosphor exhibits two strongly overlapped TL peaks at about 70 and 100 °C while the low temperature TL of the Sr4Al14025:Eu2+,Nd3+ phosphor consist of two well separated peaks with maxima at about 60 and 130 °C. Additionally, both phosphors exhibit a weak TL between 180 and 400 °C. The traps responsible for the low temperature TL peaks are the Dy3+ and Nd3+ centers situated in two different Sr sites with 7-fold and 10-fold coordination. The thermal emptying of the Dy and Nd filled traps creates ultra-long intense afterglow, which gradually decays with time and remains detectable after 220 h storage in dark. IR stimulation of beta irradiated phosphors creates intense IR stimulated luminescence, which is related to the release of electrons from the filled Dy and Nd traps.