| 초록 |
As the power of LEDs grew stronger, the need to replace currently used encapsulants has been a growing, and phosphor in glass (PIG) is acquiring great attention. As PIGs are fabricated by sintering a mixture of glass frits and phosphors, they have pores within the encapsulant. To fully understand this property, additional research to determine the relations between phosphor size, pore property and their effect on the color uniformity is needed. In this study, YAG:Ce3+ phosphors of different sizes were mixed with B2O3 – ZnO – SiO2 – K2O system glass frits by 5.0wt% and were sintered at the same temperature for the same time. The CCT, CRI, color uniformity and efficiency of these samples were measured using an integrating sphere and a spectrometer while the porosity and pore size were measured by measuring the sample cross section using a scanning electron microscope. Measured results were analyzed based on light scattering in relation with phosphor and pore size. The mixture of phosphors with different sizes caused different variables, such as scattering difference by phosphor size, porosity, and pore size. As the portion of phosphors with large particle size grew, the created pores also showed a trend in size growth, which caused different effects on each blue and yellow light waves due to the effect phosphor and pore size has on light scattering. These differences changed the color uniformity of PIGs as the mixing ratio changed. This study determined the relations between pore size and color uniformity, and also help find the ideal phosphor size combination to improve the color uniformity and efficiency of PIG. |
