Colour-tunable features in thermally stable Tb³⁺/Eu³⁺ co-doped telluro tungstate glasses for photonic applications

Abstract

Abstract The melt quenching procedure has been followed to synthesize transparent Tb 3+ singly activated and Tb 3+ /Eu 3+ co-activated TeO 2 –WO 3 –K 2 O–ZnO–Bi 2 O 3 (TWKZBi) glasses. The structural characteristics of the prepared TWKZBi glass samples were examined through x-ray diffraction. The existence of functional units corresponding to the different vibrations has been examined via Raman spectroscopy. The photoluminescent characteristics and energy transfer (ET) analysis in the Tb 3+ /Eu 3+ co-activated TWKZBi glasses were investigated in depth. Several emission peaks have been observed in Tb 3+ doped TWKZBi glasses under n-UV and blue excitations and the maximum luminescent intensity has been detected for 2.0 mol% of Tb 3+ doped TWKZBi glass sample. The emission spectra of co-doped Tb 3+ and Eu 3+ ions in the TWKZBi glasses have been studied, and the maximum ET efficiency is found to be 32.82% under n-UV excitation. The ET from sensitizer (Tb 3+ ) to activator (Eu 3+ ) ions happen through dipole–dipole interaction, as confirmed by Dexter’s and Reisfeld’s approximation. The colour-tunable emission in the prepared glass samples can be achieved via varying the content of activator ions. The decay profiles for the 5 D 4 level of Tb 3+ ions diminish with varying the concentration of Eu 3+ ions, confirming the ET from Tb 3+ to Eu 3+ ions. Furthermore, temperature-dependent photoluminescence studies show that the Tb 3+ /Eu 3+ co-doped TWKZBi glasses have good thermal stability. All the aforementioned results reveal the suitability of the Tb 3+ /Eu 3+ co-activated TWKZBi glass samples for photonic applications.

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