摘要
亚波长尺度光子晶体结构可有效提升发光二极管(LED)的光提取效率(LEE),然而在制造过程中会存在缺陷或无序.利用时域有限差分法对理想方形光子晶体结构进行了优化,在此基础上对三种无序光子晶体结构进行了仿真,研究了光子晶体结构参数的无序变化对GaN基蓝光LEDLEE的影响.结果表明,光子晶体空气孔位置和半径的无序变化使优化的80nm光子晶体LED的LEE下降,而可使非优化的60nm光子晶体LED的LEE增加;当光子晶体空气孔位置和半径的无序变化量从0到±20nm之间变化时,LEE最大会产生53.8%的浮动;光子晶体刻蚀深度的无序变化对LEE影响较小,一般可以忽略.研究结果为高性能蓝光光子晶体LED的设计制作提供了重要的理论参考.
Sub-wavelength photonic crystal can effectively improve the light extraction efficiency (LEE) of the light emitting diode (LED). However, it is inevitable to have defects, (namely disorder structures) during its fabrication. In this study, the LED model with ideal quadrate photonic crystal is optimized by using the finite-different time domain method. Three different LED structures with various disordered photonic crystals are further simulated. We investigate the influences of several stochastic variables (including position, radius, and depth of an air hole) of the photonic crystal on the LEE of GaN based blue LEDs. It can be found that regarding photonic crystal LED whose air hole radius is optimized to 80 nm, the stochastic variables of the position and radius will reduce its LEE. However, an opposite trend is found when this radius is replaced by 60 nm, which is not optimized. Furhermore, the LEE fluctuates inside to an extent of 53.8% as two stochastic variables (including the randomized position and the randomized radius) change from 0 nm to ±20 nm. The influence of the stochastic variables of the depth of air hole can be neglected since this variation is very small. The results in this paper have an important reference value for designing and fabricating high-performance blue light photonic crystal LED.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第1期460-466,共7页
Acta Physica Sinica
基金
国家重点基础研究发展计划(批准号:2009CB930503
2009CB930501)
国家自然科学基金(批准号:61077043)
教育部留学回国人员科研启动基金
山东省优秀中青年科学家科研奖励基金(批准号:BS2009NJ002)
济南大学校科研基金(批准号:XKY0917)资助的课题~~
关键词
发光二极管
无序光子晶体
光提取效率
时域有限差分法
light emitting diode, disorder photonic crystals, light extraction efficiency, finite-difference time-domain method