Physics, Materials, and Electronic Properties of Dilute-As GaNAs Semiconductors

非技术描述：该项目的重点是探索用于固态照明的新型半导体的基本材料特性。当前发光二极管（LED）中的关键障碍之一是当在高电流密度下操作时器件效率的显著降低。基于稀As GaNAs的新材料为低成本固态照明和高效太阳能电池提供了潜在的解决方案。该项目为研究生和本科生提供多学科的研究培训，从计算材料科学，材料合成到III族氮化物半导体的材料表征。外展活动包括将本科生和高中生与博士配对。学生在首席研究员的实验室进行材料和纳米技术为基础的研究工作。光电子和纳米技术领域的“实践”经验吸引学生在早期阶段追求科学和工程事业。技术描述：该项目的重点是基于混合As-N合金，特别是GaNAs的新III-氮化物技术。传统III族氮化物系统（即InGaN）的关键障碍是缺乏对非辐射过程（称为俄歇过程）的基本材料理解。稀As GaNAs有望在俄歇工艺中显示出显著的减少，从而可以导致高效率LED以及其他光电器件。研究课题包括薄膜外延、材料表征、计算材料科学和纳米结构以及物理性质表征。对这种新材料系统的合成、材料物理和电子特性的理解有望揭示LED中的效率下降问题，这为低成本和高效率的固态照明技术开辟了一条道路。此外，由于其在大光谱范围内的带隙调谐能力，稀As GaNAs可以在太阳能电池和太阳能-氢转换器件中找到应用。

Non-technical Description: The project focuses on exploring the fundamental materials properties of a new class of semiconductors for solid state lighting. One of the key barriers in current light-emitting diodes (LEDs) is a significant reduction in device efficiency when operating under high current density. The new materials based on dilute-As GaNAs offer a potential solution toward low-cost solid state lighting and high-efficiency solar cells. The project offers graduate and undergraduate students multidisciplinary research training, ranging from computational materials science, materials synthesis, to materials characterization for III-Nitride semiconductors. The outreach activities include pairing undergraduates and high-school students with Ph.D. students to perform material- and nanotechnology-based research work in the Principle Investigator's laboratory. The 'hands-on' experiences in the fields of optoelectronics and nanotechnology attract students at early stage to pursue careers in sciences and engineering. Technical Description: The project focuses on a new III-Nitride technology based on mixed As-N alloys, specifically, GaNAs. The key barrier in the conventional III-nitride system, namely InGaN, is the lack of fundamental materials understanding of the non-radiative process--referred to as the Auger process. The dilute-As GaNAs is expected to show significant reduction in the Auger process and thus could lead to high efficiency LEDs as well as other optoelectronic devices. The research tasks include thin-film epitaxy, materials characterization, computational materials science and nanostructures, and physical property characterization. The understanding of the synthesis, material physics, and electronic properties of this new material system is expected to shed light on the efficiency-droop issue in LEDs, which opens up a pathway for low-cost and high efficiency solid state lighting technology. In addition, the dilute-As GaNAs could find applications in solar cells and solar-hydrogen conversion devices because of its capability in bandgap tuning across a large spectrum range.