Chen Li-Yin, Cheng Wei-Chih, Tsai Chun-Chin, Chang Jin-Kai, Huang Yi-Chung, Huang Jhih-Ci, Cheng Wood-Hi
Opt Express. 2014 May 5;22 Suppl 3:A671-8. doi: 10.1364/OE.22.00A671.
New broadband glass phosphors with excellent thermal stability were proposed and experimentally demonstrated for white light-emitting-diodes (WLEDs). The novel glass phosphors were realized through dispersing multiple phosphors into SiO₂ based glass (SiO₂-Na₂O-Al₂O₃-CaO) at 680°C. Y₃Al₅O₁₂:Ce³⁺ (YAG), Lu₃Al₅O₁₂:Ce³⁺ (LuAG), and CaAlSiN₃: Eu²⁺ (nitride) phosphor crystals were chosen respectively as the yellow, green, and red emitters of the glass phosphors. The effect of sintering temperature on inter-diffusion reduction between phosphor crystals and amorphous SiO₂ in nitride-doped glass phosphors was studied and evidenced by the aid of high-resolution transmission electron microscopy (HRTEM). Broadband glass phosphors with high quantum-yield of 55.6% were thus successfully realized through the implementation of low sintering temperature. Proof-of-concept devices utilizing the novel broadband phosphors were developed to generate high-quality cool-white light with trisstimulus coordinates (x, y) = (0.358, 0.288), color-rending index (CRI) = 85, and correlated color temperature (CCT) = 3923K. The novel broadband glass phosphors with excellent thermal stability are essentially beneficial to the applications for next-generation solid-state indoor lighting, especially in the area where high power and absolute reliability are required.
提出了具有优异热稳定性的新型宽带玻璃荧光粉，并通过实验证明其可用于白光发光二极管（WLED）。这些新型玻璃荧光粉是通过在680°C下将多种荧光粉分散到SiO₂基玻璃（SiO₂-Na₂O-Al₂O₃-CaO）中实现的。分别选择Y₃Al₅O₁₂:Ce³⁺（YAG）、Lu₃Al₅O₁₂:Ce³⁺（LuAG）和CaAlSiN₃:Eu²⁺（氮化物）荧光粉晶体作为玻璃荧光粉的黄色、绿色和红色发光体。借助高分辨率透射电子显微镜（HRTEM）研究并证明了烧结温度对氮化物掺杂玻璃荧光粉中荧光粉晶体与非晶SiO₂之间互扩散减少的影响。通过实施低烧结温度，成功实现了量子产率高达55.6%的宽带玻璃荧光粉。开发了利用新型宽带荧光粉的概念验证器件，以产生高质量的冷白光，其三刺激坐标（x，y）=（0.358，0.288），显色指数（CRI）=85，相关色温（CCT）=3923K。具有优异热稳定性的新型宽带玻璃荧光粉对下一代固态室内照明应用具有重要意义，特别是在需要高功率和绝对可靠性的领域。
