高效高可靠LED若干关键技术研究

发布时间：2018-05-16 03:34

本文选题：发光二极管 + 发光效率　；参考：《东南大学》2017年博士论文

【摘要】：大功率半导体发光二极管(LED)作为一种新型固态光源,已被广泛应用于绿色智慧照明、可见光通信等领域。随着LED技术的进一步发展,对LED发光效率和稳定性的要求越来越高。提高LED发光效率包括提升内外量子效率方法,包括表面粗糙表面光子晶体以及新材料结构等。本文主要研究提高LED发光效率和有效热管理等关键问题。本文首先提出了基于光学邻近效应的光刻过程,采用合适的工艺条件,实现在LED表面用单次刻蚀制备分层粗化结构。通过建立了该结构的菲涅尔近场衍射理论模型,仿真分析了在光刻工艺中由光邻近效应导致LED表面粗化后的光场分布。设计了AlGaInP LED表面GaP层单次刻蚀分层粗化的实验方案,实验研究采用不同的光刻和反应离子刻蚀参数对GaP表面分层粗化程度的影响,最佳工艺参数时该LED芯片抽光效率提高了 162%。其次,为了进一步研究光子晶体结构对LED抽光效率的提高作用,本文提出了 LED表面二维六角晶格漏斗型空气孔光子晶体(PC)结构方案。通过分析并优化设计该结构参数,并提出在GaN LED表面制备该PC结构的三光束激光干涉方法,分析了激光三光束干涉图形和激光功率、光束夹角之间的关系。研制了相应的实验系统,试验探究不同激光输出功率密度与光子晶体形貌关系,获取了最佳工艺参数。基于该PC结构的GaN LED抽光效率比平面型的提高了 55.7%。本文探究了在LED表面制备纳米周期Ag/Si双曲超材料(HMMs)结构对提高LED发光性能及内量子效应的影响。通过建立数值分析模型,研究该HMMs结构对GaP LED发光效率和Purcell系数的影响。提出了在GaP LED表面制备纳米周期Ag/Si HMMs结构的实验方法,通过磁控溅射在GaP LED表面形成Ag/Si HMMs膜,再采用聚焦离子束刻蚀出纳米周期结构。结果表明,220nm周期HMMs GaP LED比平面LED的发光效率提高了 1倍,光子衰减速率提高了 2倍。本文对LED有效热管理进行研究,提出了基于LED芯片内温度测量闭环反馈式大功率LED热管理方案,建立了 LED热传导模型。基于ANSYS对大功率LED器件(CSM 360)进行散热分析,分别获得无散热、鳞片辅助散热条件下的该器件的温度分布,设计了热管集成和半导体集成一体化散热结构,研制了 80W CSM 360的恒流驱动和基于热管散热的热管理系统,保证了大功率LED稳定工作。
[Abstract]:As a new solid-state light source, high-power semiconductor light-emitting diode (LED) has been widely used in green intelligent lighting, visible light communication and other fields. With the further development of LED technology, the efficiency and stability of LED luminescence are becoming more and more important. Improving the luminescence efficiency of LED includes improving the internal and external quantum efficiency, including the photonic crystal with rough surface and the structure of new materials. This paper focuses on the key issues of improving the luminescence efficiency and effective thermal management of LED. In this paper, the process of photolithography based on optical proximity effect is proposed, and the layer coarsening structure can be fabricated by single etching on LED surface using suitable process conditions. By establishing the Fresnel near-field diffraction theory model of the structure, the light field distribution of LED surface coarsening caused by the optical proximity effect in lithography process is simulated and analyzed. The experimental scheme of single etching and coarsening of GaP layer on AlGaInP LED surface was designed. The influence of different lithography and reactive ion etching parameters on the coarsening degree of GaP surface was studied. The extraction efficiency of the LED chip was improved by 162i when the optimum process parameters were used. Secondly, in order to further study the effect of photonic crystal structure on the efficiency of LED pumping, a scheme of two-dimensional hexagonal lattice funnel-type air hole photonic crystal structure on LED surface is proposed in this paper. By analyzing and optimizing the structure parameters, a three-beam laser interference method is proposed to fabricate the PC structure on the surface of GaN LED. The relationship between laser interference pattern, laser power and beam angle is analyzed. A corresponding experimental system was developed to study the relationship between different laser output power density and photonic crystal morphology, and the optimum technological parameters were obtained. The light pumping efficiency of GaN LED based on this PC structure is 55.7% higher than that of plane type. In this paper, the effect of nanoscale Ag/Si hyperbolic supermaterial (HMMs) prepared on the surface of LED on the enhancement of LED luminescence performance and internal quantum effect has been investigated. The influence of the HMMs structure on the luminescence efficiency and Purcell coefficient of GaP LED was studied by establishing a numerical analysis model. An experimental method of fabricating nanoscale periodic Ag/Si HMMs structure on GaP LED surface was proposed. Ag/Si HMMs films were formed on the surface of GaP LED by magnetron sputtering, and then the nanoscale periodic structure was etched by focusing ion beam. The results show that the photonic decay rate and photonic decay rate of 220nm periodic HMMs GaP LED are twice as much as that of planar LED. In this paper, the effective heat management of LED is studied, and based on the closed-loop feedback high power LED heat management scheme based on LED chip temperature measurement, the LED heat conduction model is established. Based on ANSYS, the heat dissipation of high power LED device (CSM360) is analyzed. The temperature distribution of the device is obtained under the condition of no heat dissipation and scale-assisted heat dissipation, and the integrated heat dissipation structure of heat pipe integration and semiconductor integration is designed. The constant current drive of 80W CSM 360 and the heat management system based on heat pipe are developed to ensure the stable operation of high power LED.
【学位授予单位】：东南大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TN312.8

【相似文献】