Spectroscopic investigations and phonon side band analysis of Eu3+-doped multicomponent tellurite glasses

Abstract

Novel and optically efficient multicomponent tellurite glasses doped with Eu3+ ions were prepared by melt quenching procedure. Absorption, photoluminescence excitation, emission and Raman spectra analyses of the Eu3+-doped glasses have been carried out. Spectroscopic studies were performed with the Judd-Ofelt and phonon side band analyses. The local vibrational mode around Eu3+ ions and the phonon energy of the prepared tellurite glasses was estimated by the phonon side band (PSB) associated with 7F0→5D2 transition of Eu3+ ion. Both the phonon energy (ћω) and the electron-phonon coupling constant (g) were derived from the phonon side band spectrum. Radiative properties such as spontaneous transition probabilities (AT), radiative lifetime (τR) and luminescence branching ratio (βR) ratio were calculated for different excited states. Five pronounced peaks have appeared in the photoluminescence spectra (PL) as a result of the transitions from the metastable 5D0 to the ground states 7FJ (J = 0 to 4) of Eu3+ ions. The red Eu3+ emission at 612 nm corresponding to the 5D0→7F2 transition is of particular importance and its emission intensity is observed to increase significantly with growing Eu3+ ion concentration, suggesting that these multicomponent tellurite glasses are suitable candidates for red laser source applications.