Geometric Control of Strain and Optical Properties in III-Nitride Nanostructures

该项目由材料研究部（DMR）的电子和光子材料（ETM）计划和电气、通信和网络系统部（ECCS）的电子、光子和磁器件（EPMD）计划共同资助。非技术描述：由周期表中的第III族元素和氮制成的半导体是在高温超导中具有应用的重要材料。用于国防和消费系统的电力电子器件和紫外线和可见光发射器件。本研究项目的主题是通过应变对III族氮化物纳米结构的电子和光学特性进行工程化，预计将提高性能，降低功耗，并可能导致新的系统设计概念，如用于高效照明的超紧凑轻型设备，便携式或可穿戴显示器以及生物医学成像系统。该项目提高了公众对节能和无毒照明和显示技术的认识，并通过各种教育和外联活动，包括学生培训、研究生和本科生课程开发以及技术转让和启动活动，将研究成果转化为产业。该项目的科学目标是建立应变（对称和非对称）与III族氮化物纳米结构光学特性之间的关系，更具体地说，InGaN纳米盘结构。该研究结合了实验和理论方法。各种InGaN纳米盘结构表现出不同的铟成分，有源区的厚度，尺寸和形状的合成和表征的结构和光学性能。具体的研究任务是：（1）建立一个实验验证的模型，将应变与辐射特性（包括发射波长，振子强度和偏振）联系起来;（2）探索更高能量状态对InGaN纳米盘中光发射偏振特性的作用;（3）将结果扩展到其他相关的氮化物半导体异质结构。

This project is jointly funded by the Electronic and Photonic Materials (EPM) Program in the Division of Materials Research (DMR) and by the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems (ECCS).Non-Technical Description: Semiconductors made of group-III elements in the period table and nitrogen are important materials that have applications in high-power electronics and ultraviolet and visible light emitting devices used in defense and consumer systems. Engineering of electronic and optical properties of III-nitride nanostructures via strain, the topic of this research project, is expected to improve performance, reduce power consumption, and potentially lead to new system design concepts such as ultracompact light-weight devices for efficient lighting, portable or wearable displays, and biomedical imaging systems. The project increases public awareness of energy efficient and toxin-free lighting and display technologies, and translates research findings to industry via various education and outreach activities including student training, graduate and undergraduate curriculum development, and, technology transfer and start-up activities.Technical Description: The scientific objective of this project is to establish the relationship between strain, both symmetric and asymmetric, and optical properties in III-nitride nanostructures, more specifically, the InGaN nanodisk structures. The research combines both experimental and theoretical approaches. Various InGaN nanodisk structures exhibiting different indium compositions, active region thicknesses, dimensions, and shapes are synthesized and characterized for both structural and optical properties. The specific research tasks are: (1) to establish an experimentally validated model relating the strain to the radiative properties including emission wavelength, oscillator strength, and polarization; (2) to explore the role of higher energy states on the polarization properties of light emission in InGaN nanodisks; and (3) to extend the results to other related nitride semiconductor heterostructures..