Size Effect in Novel Red Efficient Garnet Nanophosphor

Nanocrystalline powders of Eu3+ doped Gd3Ga3Al2O12 (GGAG) were prepared using a modified Pechini method. The nanocrystals with the size from tens to hundreds of nanometers were obtained. For growth of single crystal GGAG:Eu the Czochralski method was utilized. The crystal structure, grain morphology, and optical properties of GGAG doped with different concentration of Eu3+ and calcined at different temperatures were investigated and discussed. The impact of grain size and Eu3+ concentration on the spectroscopic properties of Gd3Ga3Al2O12:Eu3+ was checked and analyzed. The spectroscopic properties of the nanopowders were compared to the Gd3Ga3Al2O12:Eu3+ single crystal. The influence of effective index of refraction was taken into account in the analysis of transition rates of metastable multiplet and it was found that grain size (surface area) of the nanocrystals has a huge impact on the luminescence decay time.