具有反射电极的高亮度LED芯片设计

Design of High Brightness LED Chips with Reflective Electrode

根据光学薄膜原理,针对正装LED芯片设计了5种不同方式的电极结构,得出电流阻挡层SiO2和Al反射镜叠加制备出的反射电极具有较高的反射率,光电特性明显优于常规电极制备出的LED芯片。实验结果表明,该反射电极的反射率比常规电极结构反射率高53.1%,电流阻挡层SiO2可以改进有源区的电流扩展,减小电流堆积效应,而Al作为反射镜可以降低电极对光的吸收,使其发光效率、光强分布、饱和特性曲线和发光角度明显优于常规电极结构。实验采用化学气相沉积(CVD)法配合电子束蒸发制备反射电极,芯片的光功率提高了5.6%,成功制备出高亮度LED芯片。

According to the principle of optical thin films, 5 kinds of different electrode structure were designed in the light of dress LED chip. The current blocking layer of SiO2 and A1 reflective mirror＇s reflective electrode has higher reflectivity. The photoelectric characteristics of LED chip are obviously better than the conventional electrode system. The results show that the reflectivety of the re- flection electrode is 53. 1% higher than which of the conventional electrode structure. The current bloc- king layer of SiO2 can improve quantum well＇ s current extending, reduce the current stack effect. A1 re- flective mirror can reduce the absorption of electrode so that the luminous efficiency, light intensity dis- tribution, saturation characteristic curve and light-emitting angle are all obviously better than that of the conventional the electrode structure. The chemical vapor deposition （CVD） method and electron beam evaporation were used to prepare the reflective electrode. The optical power of the chip is increased by 5.6%, so the high brightness LED chips were propared successfully.