Phonon Sideband and Intensity Parameter Analysis of Eu 3+ /Tb 3+ -Doped Zinc Sodium Borotellurite Glasses for Multicolor Emission

A spectroscopic study of Eu 3+ , Tb 3+ and Eu 3+ /Tb 3+ ions-doped zinc sodium borotellurite (ZNB) glass synthesized by a melt-quenching method was performed via photoluminescence spectra and luminescence decay. The results of X-ray diffraction showed the amorphous materials of the prepared glass, and also indicated the difference in absorption spectra between glass samples doped by Eu 3+ and Tb 3+ ions. Three phonon energies of the ZNB host lattice were found around 932 cm −1 , 1282 cm −1 , and 1892 cm −1 through the excitation spectra of Eu 3+ and Tb 3+ ions. The multiphonon relaxation rate ( W mp ) was estimated for each phonon sideband and compared with previously reported results. Intensity parameters ( Ω λ ) were determined by the Judd–Ofelt theory and their values were used to evaluate the radiative transition of Eu 3+ ions in ZNB glass, such as calculated lifetime ( τ cal ), transition probability rate ( A ), effective line width (Δ λ eff ), stimulated emission cross-section ( σ p ), and branching ratio ( β R ). Eu 3+ /Tb 3+ co-doped in ZNB glass exhibited multicolor emissions and the energy transfer process between Tb 3+ and Eu 3+ ions was confirmed based on the analysis of excitation spectra and decay time.