Enhanced Vertical Transport III-Nitride Devices through Chemical Lift-Off Techniques

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。这项研究的目的是探索一种生长和器件处理技术，以提高固态照明用发光二极管的能效并降低成本。这些照明器件广泛应用的关键挑战包括高输出功率下的寿命、绿色发射体的内部量子效率以及固态光源的成本。这些挑战来自于使用与器件层不兼容的热绝缘和电绝缘衬底材料。本研究的方法是通过两步混合生长工艺开发垂直传输器件。第一步采用了化学可溶层的低温集成；第二步探索了器件质量材料的高温过度生长。由于界面反应和杂质的相互扩散，标准的一步生长技术限制了不同材料的集成，这可以通过混合生长来避免。这项工作将系统地研究加工、再生和化学发射对这些材料的影响，并最终将这一路线的光提取和热管理优势与现有的器件技术进行比较。这项工作在国家的教育推广和潜在的经济发展两个领域都产生了重大影响。外展部分将为代表不足的群体居住的农村和城市中学的学生提供实践照明和能源工程演示。这项提案的成功实施将使调查人员为该州的其他经济发展机会做好准备，帮助俄克拉荷马州将其在能源领域的领导地位过渡到绿色技术。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." The objective of this research is exploration of a growth and device processing technique to improve the energy efficiency and reduce the cost of light emitting diodes for solid state lighting. Key challenges to the widespread implementation of these illumination devices include lifetime at high output powers, internal quantum efficiency of green emitters, and the cost of solid state sources. Such challenges result from the use of thermally and electrically insulating substrate materials which are incompatible with the device layers.The approach of this research is development of vertical transport devices through a two-step hybrid growth process. The first step employs low temperature integration of a chemically soluble layer; the second step explores the high-temperature overgrowth of device-quality material. Standard one-step growth techniques limit the integration of dissimilar materials due to interfacial reactions and interdiffusion of impurities, which can be avoided through hybrid growth. This work will systematically investigate the effects of processing, regrowth, and chemical liftoff on these materials and will ultimately compare the light extraction and thermal management benefits of this route with existing device technologies. The broader impacts of this work are significant in both the areas of educational outreach and potential economic development for the state. The outreach portion will provide hands-on lighting and energy engineering demonstrations to students at rural and urban middle schools populated by underrepresented groups. Successful implementation of this proposal will position the investigators for other economic development opportunities in the state, helping Oklahoma transition its leadership in energy to green technologies.