Abstract
Tellurite glasses doped with Er3+, Er3+/Ce3+ and Er3+/Ce3+/Yb3+, have been elaborated from the conventional melt-quenching method. It was found that both the photoluminescence (PL) intensity and the PL lifetime relative to the 4[(13/2)-> 4[(15/2) transition of Er3+ were found to increase with Ce3+ co-doping and Yb3+ tri-doping. We show that an efficient energy transfer can occur from Ce3+ and Yb3+ to Er3+. Efficient green (533 nm, 546 nm) emission spectra, associated to the H-2(11/2)-> (4)[(15/2), and (4)[(3/2)-> (4)[(15/2) transitions of Er3+ respectively, were observed. By adding Ce3+ ions, the intensities of green up-conversion emissions were found to decrease hardly do to energy transfer rate of Er3+: (4)[(11/2)-> Ce3+:F-2(5/2). Band diagram energy is proposed to explain the up-converted PL, under 980 nm excitation, in mono-doped, codoped and tri-doped glasses. The results suggest that Er3+/Yb3+/Ce3+ tri-doped tellurite glass may be a potential material for developing optical amplifiers and up-conversion optical devices. (C) 2013 Elsevier B.V. All rights reserved.