Su Jung-Chieh, Lu Chun-Lin, Chu Cheng-Wei
Department of Electronic Engineering and Graduate Institute of Electro-optical Engineering, National Taiwan University of Science and Technology, 43, Section 4, Keelung Road, Taipei, 10607, Taiwan.
Appl Opt. 2009 Sep 10;48(26):4942-6. doi: 10.1364/AO.48.004942.
This study investigates white light emitting diodes (LEDs), packaged with an omnidirectional reflector (ODR) and UV LED of 378 nm. The current work designs an ODR to solve the problems of UV leak and low phosphors conversion efficiency with a thin film structure of S/(HLH)n/air modified from a quarter-wave stack. Since an ODR is a perfect dielectric mirror for UV light, the UV leak can be eliminated and recycled to enhance phosphors conversion efficiency. By measuring the emission spectrum of a white LED with an ODR, the orientation distribution of the color properties, and the radiation power, the current study did not detect any UV leak. The average luminous intensity enhancement is 15%.
本研究对采用全向反射器（ODR）和378 nm紫外发光二极管（UV LED）封装的白光发光二极管（LED）进行了研究。当前工作设计了一种ODR，通过对四分之一波长堆叠结构S/(HLH)n/空气进行改进得到的薄膜结构，来解决紫外线泄漏和荧光粉转换效率低的问题。由于ODR对紫外线是一种完美的介质镜，因此可以消除紫外线泄漏并进行回收利用，以提高荧光粉转换效率。通过测量带有ODR的白光LED的发射光谱、颜色特性的方向分布以及辐射功率，本研究未检测到任何紫外线泄漏。平均发光强度增强了15%。
