导　　师： 刘颂豪;廖常俊

学科专业： 070207

授予学位： 博士

作　　者： ;

机构地区： 华南师范大学

摘　　要： 由于高亮度发光二极管/(HB-LED/)可应用于室外大屏幕显示，交通指示灯，汽车尾灯，液晶显示背光源等领域，甚至可进入照明领域，将引发一场照明领域发光器件的革命，因此成为近年来世界先进国家研究热点，并已经取得很大的发展。美日两国的大公司在成功研制部分结构的HB-LED同时也纷纷申请大量的专利以便于垄断行业。本论文分析了当前国内外各种LED的结构及其制作工艺，在技术上较为成熟的双异质结构基础上，我们在器件的有源区引入应变多量子阱结构，并根据实际需求增加补偿应变技术以保证发光层结构的稳定性；通过对器件外量子效率的计算，使得在器件设计有了定量的理论分析依据；并采用先进的涡轮LP-MOCVD成功制备出GalnP／GaAlInP应变多量子阱高亮度发光二极管器件。本文的主要工作如下： 1 首先介绍了LED发展的历程和将来发展的趋势，分析HB-LED的制作难点，并指出本论文的主要研究工作。 2 利用k·p能带计算的近似理论，分别分析和计算了GaInP体材料，量子阱，多量子阱以及弹性应变下的能带结构。计算结果表明，在压应变力下，量子阱的重空穴带上升，轻空穴带下降。第一重空穴在/(?/)/_x+/(?/)y方向上的有效质量减小，而轻空穴则具有负的有效质量，这对器件电注入和光辐射复合是有利的。最后还指出了量子阱结构在张应力作用下能带实现交叉的应变量。 3 对LED器件多量子阱有源区载流子输运与复合跃迁的分析。分析结果表明，有源区量子阱数越多，非平衡载流子的密度越低，势垒对非平衡载流子限制越好；通过对跃迁元的推导得出，量子阱的跃迁元比体材料的要大；量子阱的层厚比体材料的薄，自吸收比体材料的小，所以多量子阱作为器件的有源区比体材料更有优势。 High brightness light emitting diodes could be used in the fields of large outdoor display, traffic signal lights, automotive light and backlighting of liquid crystal display. It also has another potential, for example, it may be used as replacement of incandescent bulbs for lightening in the future. For being with many advantages, it has been an active subject in recent years and much progress has been made. On the basic of analysis of many kinds of LED structures, a new kind of strained layer structure has been introduced into our designed HB-LED which has been manufactured in our laboratory to demonstrate a even higher efficient light emission. Through calculation of LED external quantum efficiency, a method for design HB-LED top layer was evaluated. The main work is as following: 1 The history and trend of HB-LED were briefly described. The obstacles in developing HB-LED were analyzed and the main work in this thesis was pointed out. 2 The energy structures of GalnP//GaAlInP bulk material, quantum well, multi-quantum wells and strained quantum well were theoretically analyzed and calculated. For the compressively strained layer, the heavy-hole state is moved to higher energy and the light-hole state to lower energy due to the shear-deformation potential. 3 The carrier transportation and transition in LED active layer had been analyzed. The larger number of quantum wells are in active layer, the lower carrier density will be, and the better confinement of carrier is. The coefficient transition in quantum well is larger than that in bulk material. 4 Design of HB-LED is focused on MQWs and top layer. Compensatory MQWs for LED active layers have led to good results follow the analysis in former two chapters. Systematic analysis of current injection and light output Via external quantum efficiency of HB-LED showed mat the optimum of top layer of HB-LED is appeared to be between 15 u m and 20 u m, and at least is 5 u m. 5 GalnP, GaAlInP and

关 键 词： 多量子阱 外量子效率 发光二极管 有源区 峰值波长 反应室 外延层 子阶

领　　域： [电子电信]