Photoluminescence properties of YAG:Ce 3+,Pr 3+ phosphors synthesized via the Pechini method for white LEDs

We describe a facile route for synthesize YAG nanophosphors via Pechini-type sol-gel process for white light-emitting diodes technology. The wet-type synthesis was followed by a heat treatment at 1,000 degrees C for 4 h. We carried out a study of the luminescent properties of the YAG:Ce,Pr system varying the concentration of praseodymium from 0.125 to 2 mol% maintaining the quantity of cerium constant at 2 mol%. The diffractometric analysis confirmed the purity of the YAG phase. The luminescent analysis showed the typical Ce3+ emission arising from the 5d -> 4f transitions overlapped with the sharper Pr3+ emissions in the red region of the spectrum. The presence of energy transfer phenomenon was confirmed by PLE spectra of the samples and the appearance of concentration quenching at 0.5 mol% Pr was observed thanks to the decrease both of the intensity of praseodymium emission and mean lifetime.