Effect of Zirconium Dioxide in BaO-ZnO-B2O3-SiO2 system on Optical Properties of Color Conversion Glasses

Abstract

The effect of zirconium dioxide (ZrO₂) on the properties of color conversion glasses was examined in the BaO-ZnO-B₂O₃-SiO₂ system. The difference in refractive index between glass and phosphor affect the optical properties of the color conversion glass because of light scattering. Reducing the difference in refractive index is a method to improve the luminous efficacy of color conversion glasses. As a reference, a type of glass that contains 25 mol% of each component was used. To increase the refractive index of the glass samples, the BaO content was increased from 25 to 40 mol%, and ZrO₂ was added at levels of 1, 3, and 5 mol%. Color conversion glasses were prepared by sintering a mixture of glass and 5 wt% YAG:Ce 3+ phosphor. As a result, the refractive index of the glass was found to be dependent on the BaO and ZrO₂ contents in the BaO-ZnO-B₂O₃-SiO₂ system. As the BaO and ZrO₂ contents were increased, the luminous efficacy of the color conversion glass was improved because the refractive index difference between the glass and the YAG:Ce 3+ phosphor decreased.