Effect of temperature and activator concentration on luminescence decay of erbium-doped tellurite glass

Abstract

Multicomponent tellurite glass containing a concentration of Er +3 ranging from 8.1 × 10 19 ions cm -3 to 1.5 × 10 21ions cm -3 was studied experimentally in the 20–473 K temperature region using the methods of spectroscopy. For low concentrations of Er +3, the luminescence decay of the 4S 3 2 and 4I 11 2 levels is governed by radiative transitions and multiphonon relaxation involving the highest energy Te-O vibrations. In heavily doped samples the luminescence quenching is observed. The rate of this quenching for the 4S 3 2 level increases at about 145 K and at room temperature depends quadratically on Er 3+ concentration. This behaviour is consistent with the process of the cross relaxation via an intermediate level. Quenching of luminescence from the 4I 11 2 level in heavily doped samples is attributed to the nonradiative energy transfer from Er +3 ions to the structural defects.