CAREER: Cubic Phase Green Light Emitting Diodes for Advanced Solid State Lighting

题目：先进固态照明用三相绿色发光二极管的研究本提案的研究目标是探索三相发光二极管的基本特性，这将提供关闭可见光谱中“绿色间隙”所需的关键知识，为先进的固态照明铺平道路，并通过混色方法桥接高效照明、可靠连接和快速网络。这项拟议的研究预计将产生重大的社会和技术影响。这项研究将通过利用六边形到立方体的相变和廉价、可扩展的硅平台，为创造绿色发光二极管建立一个新的范例。由此产生的立方相氮化镓框架将产生许多分支，可能会影响能源，通信和医疗保健领域的其他微/纳米光电系统。该提案计划将技术和教育平台结合起来，包括K-12科学、技术、工程和数学教育，以提高美国的经济竞争力。首席研究员将开发一个以主题为基础的互动推广项目“固态照明”，并将在少数民族入学率高（50%）的当地中学试用课程材料。另一个重要组成部分将是创建一个便携式展览，以启发K-12学生和公众关于光和光子学的知识。所有这些材料也将在网上提供，以供广泛分发。此外，包含建议研究结果的模块将包括在本科和研究生课程中（每年约80名学生）。此外，首席研究员每年夏天将继续在研究小组中接待一名K-12教师和一名女性或代表性不足的少数民族学生。技术描述：迄今为止，基于ingan的绿色发光二极管的研究仅限于自然产生的六边形相位器件，这些器件在功率，效率，速度和带宽方面受到限制。这一问题推动了立方相氮化镓的研究。三相绿光发光二极管由于带隙降低0.2 eV，所需的铟含量降低了约10%。此外，由于它们的零极化，它们可以使辐射复合动力学提高四倍。本提案的知识价值源于对集成在纳米互补金属氧化物半导体兼容硅上的GaN器件的分析，这将揭示立方相绿色发光二极管的特性，并为其异质集成提供变革性的新知识。具体来说，控制立方相材料形成的结构机制将通过一系列实验表征技术来研究，旨在确定关键的衬底纳米图案设计，最大限度地提高立方相含量。同时，研究这些（In）GaN光子结构的辐射复合动力学及其结构-复合关系。这些发现将从缺陷（±108 cm-2）、相含量（±0.1%）、应力（±0.01%）、合金含量（±0.01%）、晶体取向、带隙和发射能（±1 meV）、振动能（±2 cm-1）、复合动力学（±1 ps）和空间均匀性（1.5 nm）等方面进行定量评估。研究结果还将用于改善绿色发光二极管的辐射重组动力学，从而彻底改变基于氮化镓的光子器件设计策略。拟议的研究将在互补金属氧化物半导体兼容硅衬底上进行，以促进可扩展性，工业应用，并产生gan -硅异质集成的新知识。所获得的知识将有助于开发新的光子器件设计，并促进对先进固态照明的更全面理解。

Abstract Title: Investigation of Cubic Phase Green Light Emitting Diodes for Advanced Solid State LightingNon-Technical Description: The research objective of this proposal is to explore the fundamental properties of cubic phase light emitting diodes that will provide the critical knowledge required to close the "green gap" in the visible spectrum paving the way towards advanced solid state lighting and bridging efficient lighting, reliable connectivity, and fast networking via color mixing approach. The proposed research is expected to have significant societal and technological impact. This research will establish a new paradigm in creating green light emitting diodes by exploiting the hexagonal-to-cubic phase transition and an inexpensive, scalable silicon platform. The resulting cubic phase GaN framework will have many ramifications that may impact other micro-/nano- electro-photonic systems in energy, communication, and healthcare. The proposal plans to combine technical and educational platforms, including K-12 Science, Technology, Engineering and Math education efforts, for increasing the economic competitiveness of the United States. The principal investigator will develop a theme-based interactive outreach program, "Solid State Lighting", and will pilot curriculum materials at local middle schools with high ( 50%) minority enrollment. Another key component will be the creation of a portable exhibit to enlighten K-12 students and the general public about light and photonics. All of these materials will also be made available online for broad distribution. Additionally, modules incorporating the findings of the proposed research will be included in undergraduate and graduate courses (~80 students annually). Furthermore, the principal investigator will continue to host one K-12 teacher and one woman or underrepresented minority student in the research group every summer.Technical Description:To date, InGaN-based green light emitting diode research has been restricted to naturally-occurring hexagonal phase devices that are limited in power, efficiency, speed, and bandwidth. This problem fueled the research for the development of cubic phase GaN. Cubic phase green light emitting diodes reduce the necessary indium content by ~10% because of a 0.2 eV lower bandgap. Also, they can quadruple radiative recombination dynamics by virtue of their zero polarization. The intellectual merit of this proposal stems from the analysis of GaN devices integrated on nano-patterned Complementary Metal-Oxide Semiconductor-compatible silicon that will shed light on the properties of cubic phase green light emitting diodes and provide transformational, new knowledge in their heterointegration. Specifically, the structural mechanisms governing cubic phase material formation will be studied through a series of experimental characterization techniques aimed at identifying critical substrate-nano-pattern designs maximizing the cubic phase content. Concurrently, the radiative recombination dynamics of these (In)GaN photonic structures will be investigated and their structure-recombination relations correlated. These findings will be quantitatively evaluated in terms of defectivity (± 108 cm-2), phase content (± 0.1%), stress (± 0.01%), alloy content (± 0.01%), crystallographic alignment, bandgap and emission energy (± 1 meV), vibrational energy (± 2 cm-1), recombination dynamics (± 1 ps), and spatial uniformity ( 1.5 nm). The results will also be exploited to improve the radiative recombination dynamics of green light emitting diodes to revolutionize GaN-based photonic device design strategies. The proposed research will be carried out on Complementary Metal-Oxide Semiconductor-compatible silicon substrates to facilitate scalability, industrial adoption, and generate new knowledge on GaN-Silicon heterointegration. The knowledge acquired will help develop new photonic device designs and facilitate a fuller understanding of advanced solid state lighting.