Enhanced photoluminescence of ZnOSiO_2 nanocomposite particles and the analyses of structure and composition

摘要

Stable blue-green photoluminescent ZnOSiO_2 nanocomposite particles exhibiting quantum efficiency as high as 34.8 under excitation at 360 nm were prepared using a spray-drying process from a feed solution that contained both luminescent ZnO nanoparticles synthesized by a solgel method and commercially-available SiO_2 nanoparticles. The effects of silica nanoparticle size and SiO_2-to-ZnO concentration ratio on the PL properties of the composite particles were investigated. The internal structure and chemical composition were investigated in detail using elemental mapping, which revealed that ZnO nanoparticles were well-dispersed within silica nanoparticle matrix. At a LiOH concentration of 0.23 M, the predicted ZnO crystallite diameter before and after spray drying was approximately constant at 3.3 and 3.6 nm, respectively. This result indicates that ZnO particle growth was inhibited and therefore the PL property of ZnO nanoparticles was stably preserved in the composite.