量子阱数量变化对InGaN/AlGaN LED的影响  

Effect of The Number of Quantum Wells on InGaN/AlGaN LED

作　　者：宋晶晶[1] 张运炎[1] 赵芳[1] 郑树文[1] 范广涵[1] 

机构地区：[1]华南师范大学光电子材料与技术研究所,广东广州510631

出　　处：《发光学报》2012年第12期1368-1372,共5页Chinese Journal of Luminescence

基　　金：省部产学研结合引导项目(2009B090300338;2010B090400192);省战略性新兴产业专项资金LED产业项目(2010A081002005);国家自然科学基金(61176043)资助项目

摘　　要：采用软件理论分析的方法分析了InGaN/AlGaN量子阱数量变化对发光二极管内量子效率、电子空穴浓度分布、载流子溢出产生的影响。分析结果表明:量子阱的个数不是越多越好,LED的光学性质和量子阱的个数并不成线性关系。量子阱个数太少时,电流溢出现象较明显;而当量子阱个数太多时,极化现象明显,且会造成材料浪费。因此应根据工作电流选择合适的量子阱个数。The optical properties of the InGaN/AlGaN light-emitting diodes（LEDs） with varied quantum well（QW） numbers are studied numerically.The simulated results show that the single quantum-well（SQW） structure has the best optical performance with small current less than 100 mA.However,the 9-QWs structure obtains higher output power and IQE than other structures when the current is larger than 700 mA,and the efficiency droop is dropped markedly from 14.10% to 5.15% at 700 mA comparing with that of the SQW structure.Therefore,9-QWs is the optimized structure for high-power LEDs.It can be explained as follows：（1） The 9-QWs structure acquires higher capacity of carrier confinement due to the smaller band bending effect and the effective hole potential barrier heights formed by the electron block layer（EBL）.（2） When the QW number is less than 9,the lower capacity of carrier confinement and lower radiative recombination rate in the active region reduce the performance of the device,though the turn-on voltage is lower.（3） When the QW number is more than 9,the structure shows higher peak internal quantum efficiency（IQE） and less serious efficiency droop compared with 9-QW structure.However,the smaller IQE and larger band bending effect make it worse for a high power structure.

关 键 词：量子阱数量 数值模拟 INGAN AlGaN发光二极管 大功率 

分 类 号：O47[理学—半导体物理]