Eu3+ concentration effect on luminescence properties of YAG:Eu3+ nanoparticles

• The nanocrystalline powders YAG:Eu were prepared by modified Pechini method.
• The dependence of luminescence intensity on Eu3+ doping concentration was studied.
• The processes leading to relaxation of excited state were discussed.
• Probabilities of radiative and nonradiative processes were calculated.
• We explain the decrease of observed lifetime with increasing Eu3+ concentration.

Nanocrystalline Eu3+-doped YAG powders were prepared by modified Pechini method. The structural properties were investigated with XRD, SEM and Raman spectroscopy. XRD pattern indicated that the phase-pure YAG:Eu3+ crystallites were obtained without the formation of any other phases. Raman spectrum revealed good homogeneity and crystallinity of synthesized nanopowders. The luminescent properties were studied by measurement of excitation and emission spectra, quantum yields and decay curves. The effect of Eu3+ concentration on 5D0 level lifetime was studied. The processes resulting in the relaxation of excited state (5D0 level) were discussed and the probabilities of radiative and nonradiative processes were calculated using the model of f–f transition intensities. It was found that the observed shortening of 5D0 level lifetime with Eu concentration is caused by increase of nonradiative process probability.