Photoluminescence enhancement of YAG:Ce nanophosphors with SiO2 additions

Co-precipitated Y3Al5O12:Ce nanophosphors with enhanced photoluminescence (PL) intensity were synthesized by introducing SiO2 in the precursor. The role of SiO2 on morphologies, PL enhancement and valence state of Ce was investigated by varying the amounts of SiO2 from 0 to 1.0 wt%. The SiO2 addition inhibited the crystal growth owing to the appearance of second phase. However, the PL intensity of YAG:Ce was largely improved with SiO2 addition. The reason for the PL enhancement was that the incorporation of Si4+ into the YAG host suppressed the further oxidation of Ce3+ to Ce4+ owing to charge compensation.