Red-Emitting Tellurite Glasses: A Combined Investigation of Physical, Structural, Optical and Luminescence Properties for Potential Wleds and Scintillation Applications

This study explores the influence of varying Europium oxide (Eu2O3) concentrations on the physical, structural, optical, and luminescence properties of boro-tellurite glasses. Glass samples were synthesized via the melt-quenching technique with Eu2O3 concentrations ranging from 0 to 3 mol%. Analytical techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and photoluminescence (PL) spectroscopy, were employed. Results revealed a increase in density and decreased molar volume with higher Eu2O3 content, indicating network expansion due to the larger ionic radius of Eu3+ ions. FTIR confirmed the presence of BO3 and BO4 units, with increased BO4 proportions suggesting the role of Eu³⁺ ions as network modifiers. Photoluminescence studies showed characteristic emissions of Eu³⁺ ions, with the maximum intensity observed at 1.5 mol% Eu2O3 before concentration quenching occurred. Judd-Ofelt analysis demonstrated high asymmetry in the Eu3+ local environment, while CIE chromaticity coordinates highlighted a reddish-orange hue, suitable for white light-emitting diode (WLED) applications. X-ray-induced luminescence showed patterns consistent with photoluminescence, with the 1.5 mol% sample achieving 27.48% scintillation efficiency compared to a bismuth germanate (BGO) crystal. These findings underline the potential of Eu3+-doped glasses as gain media for lasers and as phosphors for WLEDs, especially in indoor lighting and scintillation applications.