Concentration quenching in transparent glass ceramics containing Er3+:NaYF4 nanocrystals

In this work, we have studied the concentration quenching in transparent glass ceramics containing Er3+:NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the 4I13/2→4I15/2 emission were measured. The Er-concentration dependence of integrated intensity and lifetime of 4I13/2→4I15/2 emission are showed. With the increase of the Er3+ doping concentration, the 1.5 m fluorescence emission first increases, then decreases, and the lifetime falls gradually. With 980 nm excitation, the efficiency of the energy transfer from Er3+ to quenching centers reaches 73.73% for the sample with 4 mol% Er3+. Meanwhile, owing to the relation of fluorescence integrated intensity and Er-concentration, a dipole-dipole quenching mechanism in the framework of a limited diffusion regime has been proved. Using the limited diffusion case, the critical concentration for quenching has been determined from a fitting equation of the lifetime and Er-concentration. The fitting result shows the critical concentration for quenching is higher than the values obtained in Er-doped different glass by an order of magnitude.