物理学报2012，Vol.61Issue(12)：523-533,11.
双层光子晶体氮化镓蓝光发光二极管结构优化的研究
Structural optimization of GaN blue light LED with double layers of photonic crystals
摘要
Abstract
The GaN-based blue light LED with double layer photonic crystals is designed to enhance the vertical light extraction efficiency. The effective index approximation method is proposed and used to solve the distribution of the modes in the LED model. The geometrical parameters including the depth of the top photonic crystal d, the thickness of the embedded photonic crystal T, and the distance between the active layer and the embedded photonic crystal D are optimized. Compared with other numerical optimization, the mode analysis used in this work can dramatically save computation time and reduce complexity. In addition, it can provide more theoretical details about the influence of these geometrical parameters on light extraction efficiency. It can be found that when the surface photonic crystal satisfies the condition of d ~ A/nphcs, high order modes localized in the structure are still not cut off but the low order modes obtain less power since they are pushed away from the active layer. Hence, the light extraction efficiency reaches its maximum. The cap layer modes can be excited by the embedded photonic crystals, when this layer satisfies 100 nm ≤ T ≤ 300 nm and 100 nm ≤D ≤200 nm, the cap layer modes gather much power from the active layer and interact with the surface photonic crystals more efficiently. Hence the light extraction efficiency is dramatically improved. With our optimized parameters, the light extraction efficiency can be achieved to be up 4 times that of ordinary LED. These results shows a significant promise of designing a high-efficiency GaN-based blue light LED.关键词
发光二极管/光子晶体/模式分析/时域有限差分Key words
light emitting diode/photonic crystal/mode analysis/finite-difference time-domain分类
数理科学引用本文复制引用
高晖,孔凡敏,李康,陈新莲,丁庆安,孙静..双层光子晶体氮化镓蓝光发光二极管结构优化的研究[J].物理学报,2012,61(12):523-533,11.基金项目
国家重点基础研究发展计划（批准号：2009CB930503,2009CB930501）和国家自然科学基金（批准号：61077043）资助的课题. （）
