Micro-luminescence measurement to evidence decomposition of persistent luminescent particles during the preparation of novel persistent luminescent tellurite glasses

The preparation of tellurite glasses with persistent luminescence by adding persistent luminescent particles in the glass melt is reported. Compared to phosphate glasses, the afterglow from the tellurite glasses is low, indicating that the tellurite melt is more corrosive on the particles than the phosphate melt. However, as opposed to phosphate glasses, no emission from Eu³⁺ was detected in the photoluminescence spectra of the glasses when crushed into powder. We show that a confocal Raman microscope can be used to evidence the presence of Eu³⁺ in the glass-particles interface confirming that some oxidation of Eu²⁺ actually takes place during the preparation of the tellurite glasses.