Improvement in Durability of Red Phosphor Encapsulated by Sol-Gel Glass for Use in White Light-Emitting Diodes

Transparent glass films with homogeneously doped light emissive molecules can be prepared by using the sol-gel process. As part of our work on improving the durability of water-soluble polysilanes against UV light irradiation, we fabricated Eu(TTAhPhen-doped sol-gel glasses and studied their optical characteristics. Using a three dimensionally dense glass network protects the Eu complex from free oxygen and water in an ambi­ ent and also improves the durability without any loss of light output. By adding the Eu(TTAhPhen beyond the limit of solubility in a starting solution, we demonstrated that the glass encapsulation prevents oxidation of the Eu-complex and also preserves its excitation intensity at a wavelength of 400 nm.