서강대학교

초록/요약

Praseodymium-doped yttrium orthosilicate, Y2SiO5:Pr3+, is one of the up-conversion phosphor material that converts visible light into UV light (280 – 340 nm). However, the main draw-back of these materials is a low conversion efficiency, limiting their applications. A Yolk-shell or hollow up-converting phosphors combined with the surface plasmon resonance effect by adding silver nanoparticles as core particle can allow the enhancement of the up-converting efficiency by absorption of the visible light from the UCM and enhances the UV light emission intensity by amplification via two generation processes. Hollow hybrid composite phosphor nanomaterials with different silver nanoparticles size, different layer thickness hollow and different phosphor layer thickness were prepared to optimize the parameters to get the highest emission intensity of up-converted UV light. This can be obtained by changing the SPR wavelength and hollow space distance between silver nanoparticles and the phosphor shell and also by changing the ratio of transmission versus absorption of visible light through the phosphor layer into the hollow layer. Using silver nanoparticles was possible to enhance the emission intensity of UV light by 48.8% from the phosphor material. Using this Hollow Hybrid Composite Nanophosphor (Ag@Y2SiO5:Pr3+) in a layer by layer configuration with WO3 (Ag@Y2SiO5:Pr3+/WO3) as photochromic material, the coloration rate from WO3 was increased by 19 times and the kinetic constant was increased by 65% comparing with photochromic WO3 layer only.