Sol–gel combustion synthesis and luminescent properties of nanocrystalline YAG:Eu3+ phosphors

Abstract Eu 3+ -doped Y 3 Al 5 O 12 (YAG:Eu 3+ ) phosphors were synthesized by a facile sol–gel combustion method. In this process, citric acid traps the constituent cations and reduces the diffusion length of the precursors. YAG phase is obtained through sintering at 900 °C for 2 h. There were no intermediate phases such as YAlO 3 (YAP) and Y 4 Al 2 O 9 (YAM) observed. The charge transfer band of nanocrystalline phosphors shows a shift toward the high-energy side, compared with that of amorphous ones due to lower covalency of Eu–O bond for nanocrystalline phosphors. The higher concentration quenching in YAG:Eu 3+ nanophosphors may be caused by the confinement effect on resonant energy transfer of nanocrystalline. It also indicates that the sol–gel combustion synthesis method provides a good distribution of Eu 3+ activators in YAG host.