Combination of translucent Eu:YAG glass ceramic with LED chip

Abstract

Luminescent ceramics may exhibit less scattering and increase the conversion efficiency over prior phosphor layers. Recently, the great majority of the commercial white LED (light emitting diodes) modules realized white light by GaN blue chip adding yellow phosphor. Although it has relatively high quantum efficiency, but its performance degenerates obviously at high temperature, and also causes deviation in correlated color temperature, peak wavelength, color index. It is a big challenge for optical stability of LED products. In this paper, we reported our recent research on fabricating translucent Eu:YAG glass ceramic through high temperature solid state reaction method and using XRD, SEM measurement to confirm YAG crystal phase. The white light was observed by packaged the glass ceramic to the blue LED chip. The Eu:YAG ceramic packaged LED sample showed relatively lower Tc and better color coordinates than the YAG ceramic packaged LED sample. Additionally, since the Eu:YAG glass ceramic can be formed in any needed shape, it is convenient for the package of the LED modules. Therefore, it is expected that this glass-ceramic is a promising candidate for the realization of resin-free, high-temperature resistant, long-life white LED devices.