Energy transfer processes in Eu3+ doped nanocrystalline La2TeO6 phosphor

Abstract

La2TeO6 nanocrystals doped with Eu3+ ions have been prepared by the Pechini sol–gel process. A total of seven samples obtained with different Eu3+ concentrations (1–7%). The Eu3+ ions are usually taken as probe ions to test the local structure of the lanthanide in solids. Analyzing the luminescence has been shown two different sites for the Eu3+ ions (in good agreement with the crystallographic analysis). Moreover, the luminescence properties have been analyzed as function of the Eu3+ doping concentration in order to study the interaction between these ions. Under direct excitation into the 5D0 level (at 578nm) the corresponding decay curves show a pure exponential character independently of the Eu3+ concentration. However, the decay curves obtained for the 5D1 level becomes non-exponential for the higher doped nanocrystals samples indicating that the energy transfer processes are important.