| 초록 |
For LED application of CaS:Eu, one of alkaline earth sulfide phosphors, we investigated the effect of surface coating on the enhancement of water resistance. As coating materials, PVP/Silica and PMMA/Silica nanocomposite synthesized in this research are used. To make transparent hybrids, we controlled the size of silica particles with using Stöber method, one of the sol-gel process, and fabricated coating materials via radical polymerization. When using hydrophobic PMMA/Silica nanocomposite, the amount remained on the surface of phosphor was much more than when using hydrophilic silica particles or PVP/Silica nanocomposite. PL intensity of coated CaS:Eu was developed compared with before coating. In addition, after coated CaS:Eu was introduced in 80℃ and 80% relative humidity even during about 200 hours, PL intensity is higher than that of CaS:Eu before coating. |
