量子阱结构对含V形坑InGaN/GaN蓝光LED效率衰减的影响  

Effect of Quantum Well Structure on The Efficiency Droop of V-pits-containing InGaN/GaN Blue LED

作　　者：吕全江[1] 莫春兰[1] 张建立[1] 吴小明[1] 刘军林[1] 江风益[1] 

机构地区：[1]南昌大学国家硅基LED工程技术研究中心,江西南昌330047

出　　处：《发光学报》2017年第7期923-929,共7页Chinese Journal of Luminescence

基　　金：国家重点研发计划重点专项(2016YFB0400600;2016YFB0400601);国家自然科学基金重点项目(61334001);国家自然科学青年基金(21405076);国家自然科学地区基金(11364034);江西省自然科学基金(20151BAB207053);江西省自然科学基金(20161BAB201011)资助项目~~

摘　　要：使用MOCVD在图形化Si衬底上生长了含V形坑的InGaN/GaN蓝光LED。通过改变生长温度,生长了禁带宽度稍大的载流子限制阱和禁带宽度稍小的发光阱,研究了两类量子阱组合对含V形坑InG aN/GaN基蓝光LED效率衰减的影响。使用高分辨率X射线衍射仪和LED电致发光测试系统对LED外延结构和LED光电性能进行了表征。结果表明:限制阱靠近n层、发光阱靠近p层的新型量子阱结构,在室温75 A/cm^2时的外量子效率相对于其最高点仅衰减12.7%,明显优于其他量子阱结构的16.3%、16.0%、28.4%效率衰减,且只有这种结构在低温时(T≤150 K)未出现内量子效率随电流增大而剧烈衰减的现象。结果表明,合理的量子阱结构设计能够显著提高电子空穴在含V形坑量子阱中的有效交叠,促进载流子在阱间交互,提高载流子匹配度,抑制电子泄漏,从而减缓效率衰减、提升器件光电性能。V-pits-containing In Ga N/Ga N blue LEDs were grown on patterned Si substrate by metalorganic chemical vapor deposition（MOCVD）. A carrier confinement quantum well（QW） with a larger band gap and a light-emitting QW with a slightly smaller band gap were grown by tuning growth temperature. The effect of QW structure on the efficiency droop performance of V-pits-containing InGaN/GaN blue LED was investigated with some means to mix the two different types of QW. LED epitaxial wafers and LED photoelectric properties were characterized by high-resolution X-ray diffraction and LED test system. For the novel quantum well structure in which the confinement QW close to the n-side and the light-emitting QW close to the p-side,the droop of the external quantum efficiency is only 12. 7%,which shows a more significant improvement compared with other QW structures（16. 3%,16. 0%,28. 4%）. What＇s more,only for this kind of structure,the internal quantum efficiency does not decrease sharply with the increasing of drive current at low temperature（T≤150 K）. The results show that a reasonable design of QW structure can significantly improve the effective overlap of electron-hole pairs in V-pits-containing In Ga N/Ga N QWs,promote carriers interaction between wells,and then improve carriers matching degree,inhibit electron leakage,retard efficiency droop,and finally enhance the photoelectric properties of devices.

关 键 词：硅衬底 InGaN/GaN蓝光LED 效率衰减 V形坑 量子阱结构 

分 类 号：O484.4[理学—固体物理] TN383.1[理学—物理]