UV Photonic Crystal Light Sources

学术价值：紫外光(UV)激光器和发光二极管(LED)在高密度光存储、高分辨率激光打印、固态照明和显示方面具有潜在应用。研究人员建议利用光子能带结构来降低紫外光激光器的阈值，提高紫外光LED的效率。在制备过程中无意中引入的结构无序往往限制了光子带隙效应。研究人员提出了一种新的方法，即利用高阶能带结构。这种方法增加了特征尺寸，减少了晶体中的晶格缺陷数量。由于激子结合能大，即使在室温下，氧化锌也表现出很强的激子发射。然而，激子发射的非方向性限制了紫外光LED的效率。研究人员提出使用二维光子晶体来实现高方向性的氧化锌激子发射。更广泛的影响：研究人员设想，他们项目的成功将丰富学生、教师和他们的同事的研究和教育环境。紫外光光子晶体激光器和LED的成功研制将对短波长紧凑型光源的发展产生重大影响。研究人员将积极参与为大学预科和一年级本科生开发一门动态的、定制的、基于网络的课程，该课程涉及纳米结构材料中的光波现象。他们将在NSF资助的材料世界网络(MWN)的全球研究图库中公布他们的研究成果，供公众查看。研究人员将与国家纳米科学与工程学习与教学中心合作，制定一项实施计划，将“纳米光子学”纳入现代物理课程。他们将利用西北大学的物理课程来开发原型模块。

Hui Cao, Northwestern University0601249Intellectual Merit: Ultraviolet (UV) lasers and light emitting diodes (LEDs) have potential applications in high-density optical storage, high-resolution laser printing, solid-state lighting and display. The investigators propose to utilize photonic band structures to reduce the threshold of UV lasers and to increase the efficiency of UV LEDs. The structural disorder introduced unintentionally during the fabrication process often limits the photonic band gap effects. The investigators propose a new approach, i.e. to utilize higher-order band structures. This approach increases the feature size and reduces the amount of lattice defects in the crystals. Owing to the large exciton binding energy, ZnO exhibits strong exciton emission even at room temperature. However, the non-directionality of exciton emission limits the efficiency of UV LEDs. The investigators propose to use two-dimensional photonic crystal to make ZnO exciton emission highly directional. Broader Impacts: The investigators envision that the success of their program will enrich the research and education environment of students, teachers, and their colleagues. The successful development of UV photonic crystal lasers and LEDs will have significant impact on the development of short-wavelength compact light sources. The investigators will be actively involved with the development of a dynamic, customized, web-based course for pre-college and first year undergraduate students in the area of light wave phenomena in nanostructured materials". They will post their research results in the Global Research Gallery of the NSF funded Materials World Network (MWN) for public viewing. Working with the National Center for Learning and Teaching in Nanoscale Science and Engineering, the investigators will develop an implementation plan to insert "nanophotonics" into modern physics courses. They will use Northwestern physics classes to develop a proto-type module.