Up-conversion luminescence of Er 3+/Yb 3+/Nd 3+-codoped tellurite glasses

Abstract

Up-conversion luminescence and energy transfer (ET) processes in Nd 3+–Yb 3+–Er 3+ triply doped TeO 2–ZnO–Na 2O glasses have been studied under 800 nm excitation. Intense green up-conversion emissions around 549 nm, which can be attributed to the Er 3+: 4S 3/2→ 4I 15/2 transition, are observed in triply doped samples. In contrast, the green emissions are hardly observed in Er 3+ singly doped and Er 3+–Yb 3+ codoped samples under the same condition. Up-conversion luminescence intensity exhibits dependence of Yb 2O 3-concentration and Nd 2O 3-concentration. Up-conversion mechanism in the triply doped glasses under 800 nm pump is discussed by analyzing the ET among Nd 3+, Yb 3+ and Er 3+. And a possible up-conversion mechanism based on sequential ET from Nd 3+ to Er 3+ through Yb 3+ is proposed for green and red up-conversion emission processes.