表面等离激元增强AlGaN基深紫外LED研究

AlGaN-based deep ultraviolet light-emitting diode(DUV-LED) has huge promising applications in the field of sterilization, chemical and biological detection, polymer curing, non-line-of-sight communications, the lower luminous efficiency of the AlGaN-based DUV-LED is the key to restrict its development and applications. In this project, in the term of growth of high crystalline AlGaN-based DUV-LED structurial materials by high-temperature metal-organic chemical vapor deposition, it is proposed that surface plasmon will be employed to enhance the internal quantum efficiency of the AlGaN-based DUV-LEDs, and thus to improve its efficiency. Combinating theoretical calculations and experiments,we will deeply study the localization and transmission characteristics of electromagnetic field in the metal micro-nano structures, and widely explore the characteristic parameters of the surface plasmon, such as resonant gain factor, resonant frequency, mode volume and so on. Furthermoe, it will be mastered that the effect of the surface plasmon resonance under the different types, shape, density and size of metal particles on the light excitation rate and radiative emission rate of AlGaN based DUV-LED. The coupling model between the surface plasmon and photon in AlGaN-based DUV LED will be establized and the related mechanism of enhancing emission efficiency of the DUV LED by surface plasmon will be discover. Finally, a high-efficiency AlGaN-based DUV-LED with surface plasmon enhancing will be fabricated.

AlGaN基深紫外LED在杀菌消毒、生化探测、聚合物固化、非视距通讯等领域有着巨大的应用前景，但是AlGaN基深紫外LED发光效率低下是制约其发展和应用的关键。本课题拟在高温金属有机物气相沉积法制备出高质量AlGaN基LED结构材料的前提下，提出采用表面等离激元增强AlGaN 基深紫外LED的内量子效率，进而来提高深紫外LED的效率。采用理论计算和实验相结合，深入研究电磁场在金属微纳结构中的局域和传输特性，探索表面等离子体的共振增益因子、共振频率、模式体积等特征参数，掌握不同种类、形态、密度、大小的金属粒子形成的表面等离子体共振对AlGaN基深紫外LED发光激发速率和辐射发射速率的影响，建立表面等离激元与AlGaN基深紫外LED光子耦合模型，揭示表面等离激元增强AlGaN基深紫外LED发光效率机制，最终研制成功基于表面等离激元增强的高效率发光的AlGaN基深紫外LED。

AlGaN基深紫外LED在杀菌消毒、非视距通讯等领域有着巨大的应用前景，但是AlGaN基深紫外LED发光效率低下是制约其发展和应用的关键。本课题围绕如何提高AlGaN深紫外LED效率，开展表面等离激元增强AlGaN 基深紫外LED效率的研究。深入研究了高质量AlN模板的生长及高Al组分AlGaN的外延生长及掺杂，探索表面等离子体增强AlGaN基深紫外LED机理研究，揭示表面等离激元增强AlGaN基深紫外LED发光效率机制，最终研制成功基于表面等离激元增强的高效率发光的AlGaN基深紫外LED。在Scientific Report等期刊发表了论文8篇以上，影响因子大于3.0的SCI论文8篇，授权发明专利4项，组织召开“第十四届全国MOCVD会议”， 获“吉林省自然科学学术成果奖一等奖”1项。项目申请人荣获“中国科学院青年创新促进会优秀会员”，吉林省拔尖创新人才第三层次荣誉称号，担任了第16届半导体缺陷识别、成像与物理国际学术会议第11届国际氮化物会议（ICNS11），第一届全国宽禁带半导体学术及技术应用会议的组织委员会委员，担任了有色金属学会宽禁带半导体专业委员会委员，并入选OSA Senior Member。. .取得的主要成果和关键数据如下：.1) 揭示了AlN的生长机理，获得较高质量的n型和p型AlGaN。其中n型掺杂AlGaN为Al组分在45%， 载流子浓度5.8×1018cm-3，迁移率为80cm2/Vs。p型AlGaN的载流子浓度1×1017cm-3，迁移率4~5cm2/Vs。.2) 利用生长中断法生长AlGaN量子阱，获得了界面陡峭的高质量AlGaN 基深紫外LED 结构材料。其表面平整、无裂纹，原子力显微镜下能观察到原子台阶，表面粗糙度(RMS)<0.2nm； 5 个周期的AlGaN/AlN 多量子阱LED 结构XRD 至少观察到3 级卫星峰，且卫星峰之间能观察到清晰的次级卫星峰。.3) 明确了表面等离激元增强AlGaN深紫外LED机理：基于时域频域有限元差分法，模拟了纳米粒子的种类、尺寸、环境媒介等对表面等离激元共振波长的影响，结果表明，Al金属纳米粒子能够有效提高AlGaN深紫外LED发光效率。基于此，获得了基于表面等离激元增强的AlGaN深紫外LED。..本项目的实施，为推进AlGaN深紫外LED的反展和应用提供了前提和基础。