GaN-Based Vertical Cavity Surface Emitting Lasers and Resonant Cavity Light Emitting Diodes

morkoc, HadisVirginia Commonwealth university， intellectual merit基于垂直腔技术的更亮、更高效的光源对于完全成功的固态照明和电信是必不可少的。该研究采用新颖的外延膜生长/制造技术，用于高量子效率的氮化镓基微腔发光二极管和紫绿色光谱区域的电注入垂直腔面发射激光器。基于短波长氮化镓的垂直腔激光器将很有可能为高密度光数据存储和高速光通信以及照明提供基础。由于其方向性，光谱纯度和提高的光子提取效率，非相干微腔发射器也超越了传统的对应物，使其成为具有高显色指数和显示器的固态照明的理想选择。原位和非原位外延横向过度生长技术都将用于降低氮化镓材料中的缺陷密度。垂直空腔结构将被制造在横向生长的氮化镓的几乎无缺陷的翼区，以避免由扩展和点缺陷引起的非辐射中心。一种独特的外延横向过度生长技术将允许底部金属和/或介电反射器堆栈也用作生长掩膜。通过引入第二个横向过度生长步骤，电流传导将只允许通过器件的无缺陷有源区域，从而促进有效的空穴注入。更广泛的影响拟议的研究可以潜在地为节能和减少碳足迹的普通照明生产高亮度光源，显示器，以及用于光存储/网络的垂直激光器。由于对光存储的需求日益增长，开发密集集成的蓝色垂直腔激光器可以满足更快的读出和写入需求。考虑到所提议的设备结构的新颖性，预计会有激烈的工业合作。该计划将为学生和实习生提供跨学科学习的机会，与集团和其他地方的国际科学家互动，发展工业网络，并实现新技术对市场和环境的影响。

ECCS- 0725506Morkoc, HadisVirginia Commonwealth UniversityIntellectual MeritsBrighter and higher efficiency light sources possibly based on vertical cavity technology are imperative for fully successful solid-state lighting and telecommunications. The proposed research employs novel epitaxial film growth/fabrication techniques for high quantum efficiency GaN-based microcavity light emitting diodes and electrically injected vertical cavity surface emitting lasers in the violet-green spectral region. Short wavelength GaN-based vertical cavity lasers will very likely provide the foundation for high-density optical data storage and high-speed optical communication, and lighting. The incoherent microcavity emitters also surpass their conventional counterparts due to their directionality, spectral purity, and increased photon extraction efficiency, making them ideal for solid-state lighting with high color rendering index and displays. Both in situ and ex situ epitaxial lateral overgrowth techniques will be used to reduce defect densities in the GaN material. Vertical cavity structures will be fabricated on the nearly defect-free wing regions of the laterally overgrown GaN to avoid nonradiative centers caused by extended and point defects. A unique epitaxial lateral overgrowth technique will allow the bottom metal and/or dielectric reflector stacks, to be used also as the growth masks. By introducing a second lateral overgrowth step, the current conduction will be allowed only through the defect-free active region of the device, promoting efficient hole injection.Broader ImpactsThe proposed research can potentially produce high brightness light sources for general lighting with energy savings and reduced carbon footprint, displays, and vertical lasers for optical storage/networks. Because, the demand for optical storage is growing, development of densely integrated blue vertical cavity lasers can meet the need for faster read-out and writing. Considering the novelty of the proposed device structures intense industrial collaborations are anticipated. This proposal will provide the students and interns with opportunities for cross-disciplinary learning, interactions with international scientists in the group and elsewhere, development of industrial networking, and for realization of the impact of new technologies on the marketplace and environment.