InGaN/GaN多量子阱LED电致发光谱中双峰起源的研究  

Origins of Double Emission Peaks in Electroluminescence Spectrum from InGaN/GaN MQW LED

作　　者：陈志忠[1] 徐科[1] 秦志新[1] 于彤军[1] 童玉珍[1] 宋金德 林亮[1] 刘鹏[1] 齐胜利[1] 张国义[1] 

机构地区：[1]北京大学物理学院人工微结构和介观物理国家重点实验室,北京100871 [2]江苏伯乐达光电科技有限公司,盐城224002

出　　处：《Journal of Semiconductors》2007年第7期1121-1124,共4页半导体学报（英文版）

基　　金：国家自然科学基金资助项目(批准号:60406007)~~

摘　　要：研究了MOCVD生长的具有双发射峰结构的InGaN/GaN多量子阱发光二极管(LED)的结构和发光特性.在透射电子显微镜(TEM)下可以发现量子阱的宽度不一致,电致发光谱(EL)发现了位于2.45eV的绿光发光峰和2.81eV处的蓝光发光峰.随着电流密度增加,双峰的峰位没有移动,直到注入电流密度达到2×104mA/cm2时,绿光发光峰发生蓝移,而蓝光发光峰没有变化.单色的阴极荧光谱(CL)发现绿光发射对应的发光区包括絮状区域和发光点,而蓝光发射对应的发光区仅包含絮状区域.通过以上的结果,我们认为蓝光发射基本上源于InGaN量子阱发光,而绿光发射则起源于量子阱和量子点的发光.InGaN/GaN multiple quantum well （MQW） light emitting diode （LED） grown by MOCVD. Transmission electron microscopy （TEM）, electroluminescence wafers with two emission peaks were （EL）, and cathodoluminescence （CL） measurements were performed to study the recombination mechanism of the InGaN QWs. It was found that there are different widths of quantum wells in TEM images. Green and blue emissions were separately observed in the EL spectra, which are located at 2.45 and 2.81eV,respectively. The wavelengths for both the blue and green emission do not shift until the injec- tion level reaches 2 × 10^4mA/cm^2. In monochromatic CL images, the green emission comes from randomly distributed dots and floccules that occupy almost the whole surface. The blue emission comes from the floccules only. It can be concluded that the blue emission is attributed to the irradiative recombination in the QWs,and the green emission is attributed to that in wider QWs and In-rich QDs.

关 键 词：氮化镓 发光二极管 多量子阱 透射电子显微镜 电致发光谱 阴极荧光谱 

分 类 号：TN383.1[电子电信—物理电子学]