Luminescence enhancement of Y2O3:Eu3+ and Y2SiO5:Ce3+,Tb3+ core particles with SiO2 shells

This paper reports on the luminescence and microstructural features of oxide nano-crystalline (Y2O3:Eu3+) and submicron-sized (Y2SiO5:Ce3+,Tb3+) phosphor cores, produced by two different synthesis techniques, and subsequently coated by an inert shell of SiO2 using a sol–gel process. The shells mitigate the detrimental effect of the phosphor particle surfaces on the photoluminescence emission properties, thereby increasing luminous output by 20–90%, depending on the core composition and shell thickness. For Y2O3:Eu3+, uniformly shaped, narrow particle size distribution core/shell particles were successfully fabricated. The photoluminescence emission intensity of core nanoparticles increased with increasing Eu3+ activator concentration and the luminescence emission intensity of the core/shell particles was 20–50% higher than that of the core particles alone. For Y2SiO5:Ce3+,Tb3+, the core/shell particles showed enhancement of the luminescence emission intensity of 35–90% that of the core particles, depending on the SiO2 shell thickness.