The effect of SiC addition on photoluminescence of YAG:Ce phosphor for white LED

An effective way of improving photoluminescence (PL) of YAG:Ce by addition of small amount of SiC and sintering in air was described. The breakdown of SiC during sintering process in air was employed to provide the presence of SiO2 and CO both of which are known to be beneficial in enhancing the PL of YAG:Ce phosphor. SiC in the form of a fine powder was added to YAG:Ce powder and sintered to densities of >99% of theoretical density. The highest luminescence was measured in sample containing 0.08 wt% SiC. The effect of the formed SiO2 and CO was discussed and their contribution to the emission intensity was assessed. The enhancement of PL intensity is attributed to the formation of vacancies, both on Y sub-lattice and on oxygen sub-lattice and their ability to release the electrons for subsequent reduction of Ce4+ to Ce3+ which plays a role of luminescence activator.