Ding Xinghuo, Gui Chengqun, Hu Hongpo, Liu Mengling, Liu Xingtong, Lv Jiajiang, Zhou Shengjun
Appl Opt. 2017 May 20;56(15):4375-4380. doi: 10.1364/AO.56.004375.
Distributed Bragg reflectors (DBR) with metal film on the bottom have been demonstrated to further improve the light output power of GaN-based light-emitting diodes (LEDs). Periods of TiO/SiO stacks, thickness of metal film, and material of metallic reflector were designed and optimized in simulation software. The maximal bandwidth of double-DBR stacks have reached up to 272 nm, which was 102 nm higher than a single-DBR stack. The average reflectance of LEDs with wavelength from 380 nm to 780 nm in double-DBR stacks is 95.09% at normal incident, which was much higher than that of a single-DBR stack whose average reflectance was 91.38%. Meanwhile, maximal average reflectance of LEDs for double-DBR stacks with an incident angle from 0 to 90° was 97.41%, which was 3.2% higher than that of a single-DBR stack with maximal average reflectance of 94.21%. The light output power of an LED with double-DBR stacks is 3% higher than that of an LED with a single-DBR stack, which was attributed to high reflectance of double-DBR stacks.
底部带有金属膜的分布式布拉格反射器（DBR）已被证明可进一步提高基于氮化镓的发光二极管（LED）的光输出功率。在模拟软件中对TiO/SiO堆栈的周期、金属膜厚度和金属反射器材料进行了设计和优化。双DBR堆栈的最大带宽已达到272nm，比单DBR堆栈高102nm。双DBR堆栈中波长在380nm至780nm之间的LED在垂直入射时的平均反射率为95.09%，远高于单DBR堆栈的平均反射率91.38%。同时，双DBR堆栈在入射角为0至90°时的最大平均反射率为97.41%，比最大平均反射率为94.21%的单DBR堆栈高3.2%。具有双DBR堆栈的LED的光输出功率比具有单DBR堆栈的LED高3%，这归因于双DBR堆栈的高反射率。
