| 초록 |
The development of phosphor-in-glass (PIG) for light emitting diode (LED) encapsulants has been conducted to achieve high luminous efficacy, focusing on achieving a low glass transition temperature and high refractive index by using various glass modifiers. However, an investigation on the interaction between the blue light and pores from the LED chip and PIG plate, respectively, is needed to understand the effect of light scattering on the optical properties of a PIG. In this study, various glass compositions based on the SiO2-B2O3-ZnO glass system were prepared to understand the effect of modifiers (Li2O, Na2O, WO3, La2O3) on the viscosity and microstructural characteristics of the PIG. The pore properties, such as the mean pore size and the porosity, are strongly related to the optimization scattering coefficient, where the chances of blue light absorption by phosphors increase. The PIGs with intermediate mean scattering coefficient values showed higher luminous efficacy compared to others. This is considerably influenced by the amount of scattering, which is highly related with pore properties. These results indicate that the optical properties can be improved by modifying the microstructure of PIGs. |
