Department of Chemistry, Kookmin University , Seoul 136-702, Republic of Korea.
ACS Appl Mater Interfaces. 2015 Mar 4;7(8):4549-59. doi: 10.1021/am507237n. Epub 2015 Feb 23.
This paper reports the combined optical effects of a two-dimensional (2D) SiNx photonic crystal layer (PCL)-assisted Lu3Al5O12:Ce (LuAG:Ce) green ceramic-plate phosphor (CPP) and a free-standing (Sr,Ca)AlSiN3:Eu red film phosphor to enhance luminous efficacy, color rendering index (CRI), and special CRI (R9) of LuAG:Ce CPP-capped white light-emitting diodes (LEDs) for high-power white LEDs at 350 mA. By introducing the 2D SiNx PCL, the luminous efficacy was improved by a factor of 1.25 and 1.15 compared to that of the conventional flat CPP-capped LED and the thickness-increased CPP-capped LED (with a thickness of 0.15 mm), respectively, while maintaining low color-rendering properties. The combining of the free-standing red film phosphor in the flat CPP-capped, the 2D PCL-assisted CPP-capped, and the thickness-increased CPP-capped LEDs led to enhancement of the CRI and the special CRI (R9); it also led to a decrease of the correlated color temperature (CCT) due to broad wavelength coverage via the addition of red emission. High CRI (94), natural white CCT (4450 K), and acceptable luminous efficacy (71.1 lm/W) were attained from the 2D PCL-assisted LuAG:Ce CPP/free-standing red film phosphor-based LED using a red phosphor concentration of 7.5 wt %. It is expected that the combination of the 2D PCL and the free-standing red film phosphor will be a good candidate for achieving a high-power white CPP-capped LED with excellent CRI.
本文报道了二维（2D）氮化硅（SiNx）光子晶体层（PCL）辅助 Lu3Al5O12:Ce（LuAG:Ce）绿色陶瓷板荧光粉（CPP）和独立式（Sr,Ca）AlSiN3:Eu 红色荧光粉的组合光学效应，以提高在 350 mA 下大功率白色 LED 的 LuAG:Ce CPP 覆盖型白光 LED 的流明效率、显色指数（CRI）和特殊 CRI（R9）。通过引入 2D SiNx PCL，与传统的平面 CPP 覆盖型 LED 和厚度增加的 CPP 覆盖型 LED（厚度为 0.15mm）相比，分别提高了 1.25 倍和 1.15 倍的流明效率，同时保持了较低的显色性能。独立式红色荧光粉在平面 CPP 覆盖型、2D PCL 辅助 CPP 覆盖型和厚度增加的 CPP 覆盖型 LED 中的结合，提高了 CRI 和特殊 CRI（R9）；由于添加了红色发射，宽波长覆盖范围导致相关色温（CCT）降低。在 2D PCL 辅助 LuAG:Ce CPP/独立式红色荧光粉基 LED 中，红色荧光粉浓度为 7.5wt%，实现了高 CRI（94）、自然白光 CCT（4450K）和可接受的流明效率（71.1lm/W）。预计 2D PCL 和独立式红色荧光粉的结合将成为实现具有优异 CRI 的大功率 CPP 覆盖型白色 LED 的良好候选方案。
