Engineering Strain in InGaN/GaN Multiple Quantum Wells for Improved Optical Devices

这项资助由电子、通信和网络系统(ECCS)部的电子、光子学和磁性器件(EPMD)计划和材料研究部(DMR)的电子和光子材料(EPM)计划联合资助。拟议的研究通过实验和理论研究解决与量子阱中材料生长和应变控制有关的基本问题。这项工作的成果包括新的材料生长技术和光学器件技术，这些技术对于推动当前最先进的LED技术至关重要。通过使设备能够以更高的注入电流运行，固态照明的成本有望获得巨大的优势。研究生和本科生都将参与这项研究，并将接受跨学科领域的培训。拟议的研究为该学院的研究生和本科生提供了一个独特的机会，让他们获得固态照明和光学显示器领域的跨学科培训和研究经验。这些学生将成为先进照明技术的下一代领导者。该项目的目标是通过申请的资金将技术和科学成果与工业相结合。提出了利用金属有机化学气相沉积(MOCVD)生长材料的方法，以控制应变对GaN基器件的影响，并改善发光二极管(LED)的量子效率和下垂等特性。应变平衡多量子阱(SBMQW)结构由厚的InxGa1-xN模板制成，在其上生长xy的InyGa1-YN/GaN多量子阱(MQW)。它们将由张应力GaN势垒和压应力InyGa1-Yn势垒组成。将探索不同的x，y值和势垒厚度，以评估它们对发射波长的影响。我们将探索平衡拉应力和压应力的设计，以使多量子阱与InxGa1-xN衬底的晶格参数相匹配。实验研究将得到应变理论模型的支持。一个特殊的MOVD反应器将被用来减少气相反应和增加InN的成分。通过适当调整生长速率和温度来优化InGaN衬底厚度。我们将探索平面和侧壁LED结构，以展示所提出的材料应变研究的优势，并获得比传统InGaN/GaN量子阱结构更长的发射波长和更好的外量子效率。这项研究将通过实验和理论研究，加深对InGaN/GaN多量子阱应变的基本认识。它将使LED技术达到最先进的水平。

This grant is funded jointly by the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems (ECCS) and by the Electronic and Photonic Materials (EPM) Program in the Division of Materials Research (DMR).The proposed research addresses fundamental issues related to material growth and control of strain in Quantum-Wells through experimental and theoretical studies. The outcomes of this work include new material growth techniques and technology of optical devices that are vital for advancing the current state of the art LED technology. An enormous advantage is expected in the cost of solid state lighting by enabling device operation with higher injection current. Both graduate and undergraduate students will be involved in the research and will be trained in interdisciplinary areas. The proposed research is a unique opportunity for graduate and undergraduate students at to acquire interdisciplinary training and research experience in the field solid state lighting and optical displays. These students will be positioned to become the next generation leaders in advanced lighting technology. The project's goal is to integrate technical and scientific achievements through this requested funding with industries. Material growth approaches using Metal Organic Chemical Vapor Deposition (MOCVD) are proposed to allow control of the impact of strain on GaN based devices and improve the characteristics of Light Emitting Diodes (LEDs) such as quantum efficiency and droop. Strain balanced multiple quantum well (SBMQW) structures made of a thick InxGa1-xN template on which InyGa1-yN/GaN Multi-Quantum-Wells (MQWs) with x y will be grown. They will consist of tensile-stressed GaN barriers and compressive-stressed InyGa1-yN wells. Different x, y values and well, barrier thicknesses will be explored to evaluate their impact on emission wavelength. Designs will be explored where the tensile and compressive stresses are balanced out allowing MQWs to match the lattice parameter of the InxGa1-xN substrate. The experimental studies will be supported by theoretical modeling of strain. A special MOVD reactor will be employed to reduce gas phase reactions and increase the InN composition. The growth rate and temperature will be suitably adjusted to optimize the thick InGaN substrates. Planar and side-wall LED structures will be explored to demonstrate the advantages of the proposed material strain studies and obtain longer emission wavelengths and better External Quantum Efficiency than conventional InGaN/GaN QW structures. The research will advance the basic understanding of the strain in InGaN/GaN Multi-Quantum-Wells through experimental and theoretical studies. It will allow to advance the current state of the art LED technology.