Effect of Yb3+ on the Structural and Visible to Near-Infrared Wavelength Photoluminescence Properties in Sm3+-Yb3+-Codoped Barium Fluorotellurite Glasses

Various Color Light Emission from Single, Double, and Triple Eu3+/Tb3+/Tm3+ Doped Borate Glass Excited by UV Light

Lithium-aluminum-borate glasses doped with single, double, or triple Tm3+, Tb3+, or Eu3+ ions, respectively, at several concentrations were prepared. Structural characterization was performed using optical absorption and luminescence spectroscopy. The transition for the rare earth ions under study was observed in optical absorption and some for-host glass at wavelengths less than 300 nm. The luminescence of Eu3+, Tb3+, and Tm3+ is presented as bright red, green, and blue emissions, respectively. White light was produced by adjusting the excitation wavelength and doping concentration of Tm2O3, Eu2O3, and Tb4O7. The sample doped with triple rare earth ions produced color emissions from Tb and Tm to Eu, which varied in hue based on the excitation wavelengths of 350, 360, and 370 nm. The glass samples under investigation may be promising for optoelectronic devices and security applications such as data encryption.

Structural characterization of a new fluorophosphotellurite glass system

While phosphotellurite glasses have superior properties over SiO₂-based glasses for many applications in optoelectronics and photonic devices, their high hydroxyl content limits their use in the mid-infrared range. This drawback can be overcome by fluoride addition to the formulation. In this work, we report the preparation, optical, and structural characterization of new glasses in the ternary system TeO₂-xNaF-NaPO₃ having the compositions 0.8TeO₂-0.2[xNaF-(1 - x)NaPO₃] and 0.6TeO₂-0.4[xNaF-(1 - x)NaPO₃] (0 ≤ x ≤ 1) obtained by the traditional melt-quenching method and labeled as T8NNx and T6NNx, respectively. Differential scanning calorimetry (DSC) reveals high thermal stability against crystallization, with T_x-T_g varying from 80 to 130 °C, depending on fluoride/phosphate ratios. Raman spectroscopy suggests that the network connectivity increases with increasing phosphate concentration. ¹²⁵Te, ²³Na, ³¹P, and ¹⁹F NMR spectroscopy provides detailed structural information about Te-O-P, Te-F, Te-O-Te, P-O-P, and P-F linkages and the charge compensation mechanism for the sodium ions. The present study is the first comprehensive structural characterization of a fluorophosphotellurite glass system.