CAREER: Continuous, Vapor-phase Manufacturing of Anisotropic Silicon Nanostructures for Optoelectronic Applications

这项教师早期职业发展（Career）资助将创建全新的仅气相制造路线，以实现不同类型和形状的硅纳米结构。硅纳米结构在发光器件（led）和其他光电器件中具有巨大的应用潜力。控制纳米结构的形状，无论是球形的还是细长的，都可以在这些应用中实现多功能性。各向异性硅纳米结构因其不同于球形纳米结构的光电特性而受到越来越多的关注，并能显著改善led和其他光电器件的性能。目前的挑战是，制造各向异性硅纳米结构的制造策略需要高温、长反应时间、批量处理或有毒溶剂工艺，这严重限制了它们的部署和融入现有的制造基础设施。该奖项支持研究发现、表征和建模新型纯气相技术，用于使用流过工艺合成硅纳米棒，包括等离子体反应器。这些技术提供了可持续性和可扩展性，并与器件制造流程无缝集成，因此有利于开发利用各向异性硅纳米结构独特和新颖特性的新型多功能器件。一个社会效益是节能设备的可用性将减少化石燃料的消耗。本研究从工程、材料科学、等离子体科学和制造的不同角度深入研究纳米技术。在纳米技术在能源设备、消费产品、健康和医疗技术中越来越普遍的时候，这项工作的交叉性质将被用来改善工程教育、少数民族和女性学生对工程的参与，以及广泛的公众对纳米技术的理解。一些拓展活动将包括斯巴达夫人工程营和科学节。基于等离子体反应器的无毒半导体纳米晶体合成方法在产量、纳米晶体尺寸和表面特性可调、尺寸分散性窄、结晶度可控等方面是最成功的方法之一。尽管这些反应器具有灵活性，但迄今为止，使用流过式等离子体反应器生产的纳米结构完全是球体各向同性的，这限制了等离子体方法的实用性。这项研究是利用等离子体控制纳米结构形状的一个突破，它试图将等离子体与其他气相方法结合使用，合成具有可调性能的硅纳米棒。该项目的目标是为硅纳米棒的合成创造一种新的、连续的气相途径，同时进行原位反应表征，以构建等离子体环境中纳米结构生长的模型。这项工作将建立在光电功能纳米结构库的基础上，这些纳米结构既便宜又环保无毒，同时填补了等离子体反应器用于多功能纳米制造的知识空白。

This Faculty Early Career Development (CAREER) grant will create brand new vapor-phase only manufacturing routes for achieving silicon nanostructures of varying types and shapes. Silicon nanostructures have great potential for use in light-emitting devices (LEDs) and other optoelectronic devices. Exerting control over the nanostructure shape, whether spherical or elongated, enables versatility in these applications. Anisotropic silicon nanostructures have attracted increasing attention because they demonstrate optoelectronic characteristics that differ from those of spherical nanostructures and can offer dramatic improvement in the performance of LEDs and other optoelectronic devices. The challenge is that current manufacturing strategies for making anisotropic silicon nanostructures require high temperatures, long reaction times, batch processing, or toxic solvent processes, severely limiting their deployment and incorporation into existing manufacturing infrastructure. This award supports research into discovering, characterizing, and modeling novel vapor-phase only techniques for synthesizing silicon nanorods using flow-through processes, including plasma reactors. These techniques offer sustainability and scalability paired with seamless integration into device manufacturing streams, therefore benefitting the development of new versatile devices that exploit the unique and novel properties of anisotropic silicon nanostructures. One societal benefit is that the availability of energy-efficient devices will reduce fossil fuel consumption. This research delves into nanotechnology from the diverse standpoints of engineering, materials science, plasma science, and manufacturing. The cross-cutting nature of this work will be leveraged to improve engineering education, engagement of minority and female students in engineering, and broad public understanding of nanotechnology at a time when it is increasingly ubiquitous in energy devices, consumer products, and health and medical technology. Some of the outreach activities will involve Lady Spartans engineering camp and Science Festivals.Plasma-based reactor approaches for the synthesis of nontoxic semiconductor nanocrystals are some of the most successful methods in terms of production yield, tunable nanocrystal size and surface properties, narrow size dispersity, and controllable crystallinity. Despite the flexibility of these reactors, to date the nanostructures produced using flow-through plasma reactors have been exclusively spherically isotropic, limiting the usefulness of the plasma approach. This research represents a breakthrough in using plasmas to control the shape of nanostructures by seeking to use them in combination with other vapor-phase approaches to synthesize silicon nanorods with tunable properties. The objectives of this project are to create a novel, continuous, vapor-phase route for the synthesis of silicon nanorods while simultaneously performing in-situ reaction characterization to construct a model of nanostructure growth in the plasma environment. This work will build on the library of optoelectronically functional nanostructures that are inexpensive and environmentally nontoxic while filling knowledge gaps in the use of plasma reactors for versatile nanomanufacturing.