EAGER Self-Catalyzed Growth of Patterned GaAsSb and GaAsSbN Nanowires for Optoelectronic Devices

美国国家科学基金会使用探索性研究的早期概念拨款（EAGER）资助机制来支持在未经测试但具有潜在变革性的研究思路或方法的早期阶段的探索性工作。这个EAGER项目是由于Dear Colleague Letter NSF 16-080邀请来自历史上的黑人学院和大学的申请者提交提案，以加强该机构教师的研究能力而获得的。北卡罗莱纳农业和技术州立大学的项目提出了对某种纳米线集成带隙工程的全面研究。该项目的成果可能在安全、量子通信、光伏和医疗领域具有广泛的技术应用。由于半导体纳米线具有更好的光学捕获特性和易于径向应变松弛的大宽高比，因此可以对其一维结构进行操作，从而实现物理、电子和光学特性的独特组合。该项目的重点是针对GaAsSb和稀氮化GaAsSbN纳米线集成的带隙工程的综合研究，这是下一代可调谐、高性能纳米级源和探测器的潜在候选者，跨越了短波红外区域的很大一部分。该项目的目标是探索NW阵列间距对GaAsSb和GaAsSbN NWs在（111）Si上的生长动力学、结构、带隙工程和光学性质的影响。将采用多种表征技术来研究表面活性剂Sb的作用，以及如何在NW阵列中操纵它来完成带隙工程、带隙的独立调谐和光学特性，以获得具有高光学性能的期望带隙。此外，将稀释量的氮掺入GaAsSb合金中，已知在薄膜中表现出独特而有利的光电性能，尽管被点缺陷的存在所抵消。上述两种合金的实验工作将分别以生长动力学和光学特性的时域有限差分和有限元建模模拟为指导。

The National Science Foundation uses the Early-concept Grants for Exploratory Research (EAGER) funding mechanism to support exploratory work in its early stages on untested, but potentially transformative, research ideas or approaches. This EAGER project was awarded as a result of the invitation in the Dear Colleague Letter NSF 16-080 to proposers from Historically Black Colleges and Universities to submit proposals that would strengthen research capacity of faculty at the institution. The project at North Carolina Agricultural and Technical State University proposes a comprehensive investigation of the band gap engineering in a certain nanowire ensemble. The results of this project could have wide-ranging technological applications in security, quantum communications, photovoltaics and medical fields. With better optical trapping features and a large aspect ratio facilitating radial strain relaxation, one-dimensional architecture of semiconductor nanowires (NWs) can be manipulated for a distinct combination of physical, electronic and optical properties. The focus of this project is geared towards comprehensive investigation of the band gap engineering in the patterned array of a GaAsSb and dilute nitride GaAsSbN nanowire ensemble, which is a potential candidate for implementation in next-generation tunable, high performance nanoscale sources and detectors spanning a significant portion of the short wave infrared region. This project's objective is to probe the effects of NW array pitch on the growth kinetics, structure, band gap engineering, and optical properties of patterned GaAsSb and GaAsSbN NWs on (111)Si grown by self-assisted molecular beam epitaxy. A variety of characterization techniques will be employed to investigate the role of the surfactant, Sb, and how it can be manipulated in NW array to accomplish the band gap engineering, independent tuning of the band gap, and optical characteristics to achieve the desired band gap with high optical performance. Further, incorporating a diluted amount of nitrogen to the GaAsSb alloy is known to exhibit distinct and favorable optoelectronic properties in thin films, though offset by the presence of point defects. The experimental work on both of the above alloys will be guided by finite difference time domain and finite element modeling simulations of the growth kinetics and optical characteristics, respectively.