UNS: Nanowire Growth on inductively heated metal films: new reaction diagnostic and pathways towards roll-to-roll processing

UNS：感应加热金属薄膜上的纳米线生长：新的反应诊断和卷对卷加工途径

• 批准号: 1510024
• 负责人: Tobias Hanrath
• 金额: $ 30万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1510024&HistoricalAwards=false
• 关键词: UNS; Nanowire; Growth; inductively; heated

1510024 (Hanrath)Semiconductor nano wires (NWs) are essential building blocks of many emerging nanotechnologies. The technological impact of NWs ranges from energy technologies, optoelectronics, and new applications emerging at the intersection of nano- and biotechnology. In the case of energy storage technologies, silicon nano wires (Si NWs) present one of the most attractive electrode materials for high-capacity lithium ion batteries (LIB). Si NWs are also poised to play a key role in emerging solar energy technologies and have garnered significant interest as electrodes in next-generation photoelectrochemical cells. Beyond energy technologies, NWs also have potential as components in a range of emerging optoelectronic and nanobiotechnologies. Multicolor light emitting diodes (LEDs) have been made possible by controlling the composition of the NW, for example, GaN, CdS, and CdSe, for ultraviolet, visible, and near-infrared emission. Precise control over the NW surface functionalization has enabled the fabrication of NW-based chemical and biosensors, including multiplexed electrical detection of cancer markers and detection of single viruses. Vertical Si NW electrode arrays have also been demonstrated as a promising platform to interface with nerve cells to enable neural prosthetics and studies of neuronal circuits in vivo. To meet the growing expectations generated by the rapid progress with NW prototypes, attention in the field is now shifting to the design of scalable and cost-effective processing methodologies. The scale-up challenge is particularly prominent in battery applications requiring high production volumes; e.g.; a 85 kWh battery for en electric vehicle would require approximately 40 kg of Si NWs for the anode. The approach to fabricate NW devices introduced in this proposal is aimed at advancing that goal. Aside from the technical considerations of NW growth mechanism and fabrication methods, there are also important environmental and health aspects to consider. Due to their small size and high mobility NWs and nanotubes have raised concerns about asbestos-like effects. The NW processing technology developed in this project grows NW directly on the current collector metal; this eliminates separate processing of the NW raw material and mitigates potential exposure steps and facilitates the direct integration into the desired device structure.Intellectual Merit:The proposed research is based on recent discoveries in the PI's lab that Si and Ge NWs can be fabricated on resistively and inductively heated metal surfaces submersed in a fluid precursor environment. This approach provides an opportunity to study outstanding fundamental scientific questions concerning the mechanism and rate-determining step of NW growth. The focus on Si NW growth on Cu films as a model systems is motivated by the technological importance of Si NWs and the prospect of advancing NW processing technique to address outstanding challenges concerning scalable fabrication and device integration. The main objective is to establish the fundamental engineering principles for NW growth on flexible substrates and to enable their processing via roll-to-roll processes. The proposed research is structured along three main aims: to (i) establish the fundamental growth mechanism of NWs grown on heated metal films, (ii) understand the complex interplay between reaction kinetics and precursor transport phenomena and (iii) analyze, design and demonstrate NW growth integrated into a roll-to-roll process. The innovative character of the proposed work is in applying resistive and inductive heating of bulk metal foils as a precisely programmable activation technique to initiate NW growth. The fast dynamic response of the reactor system presents an opportunity to gain new insights into the fundamental thermodynamics and kinetics of NW nucleation and growth. The current-voltage and temperature transients of the heated metal will be investigated as a diagnostic tool to study the dynamics of NW growth. The versatility of the reactor design could provide a foundation to spur advances in other areas of nanostructure formation at heated surfaces.Broader Impacts :The technology in this project could have far-reaching industrial applicability as well as use in medical applications. In addition,the PI will leverage established connections to K-12 programs to develop interactive learning modules. The engagement of high school teachers should have effects in illustrating nano fabrication opportunities and challenges to the next generation of scientists and engineers. The PI will work with the learning lending library of the Cornell Center for Materials Research to make the module freely available to be used in high school science classes nationwide. The educational activities will integrate scientific discoveries into the undergraduate and graduate classrooms by creating a new interdisciplinary design course; this module will provide students with the required skills to conceive, design, and evaluate the feasibility of new fabrication processes and chemical products.

1510024 (Hanrath)半导体纳米线 (NW) 是许多新兴纳米技术的重要组成部分。纳米线的技术影响范围包括能源技术、光电子学以及纳米技术和生物技术交叉领域出现的新应用。就储能技术而言，硅纳米线（Si NW）是高容量锂离子电池（LIB）最具吸引力的电极材料之一。硅纳米线也有望在新兴太阳能技术中发挥关键作用，并作为下一代光电化学电池的电极引起了人们的极大兴趣。除了能源技术之外，纳米线还具有作为一系列新兴光电和纳米生物技术组件的潜力。通过控制 NW（例如 GaN、CdS 和 CdSe）的成分，可以实现紫外、可见光和近红外发射的多色发光二极管 (LED)。 对纳米线表面功能化的精确控制使得基于纳米线的化学和生物传感器的制造成为可能，包括癌症标记物的多重电检测和单一病毒的检测。垂直硅纳米线电极阵列也被证明是一个有前途的与神经细胞连接的平台，以实现神经修复和体内神经元回路的研究。为了满足 NW 原型的快速发展所产生的日益增长的期望，该领域的注意力现在转向可扩展且具有成本效益的处理方法的设计。在需要高产量的电池应用中，扩大规模的挑战尤为突出；例如。;用于电动汽车的 85 kWh 电池需要大约 40 kg 的硅纳米线作为阳极。本提案中引入的制造纳米线器件的方法旨在推进这一目标。除了纳米线生长机制和制造方法的技术考虑之外，还需要考虑重要的环境和健康方面。由于纳米线和纳米管尺寸小且迁移率高，引起了人们对类石棉效应的担忧。本项目开发的纳米线加工技术直接在集流体金属上生长纳米线；这消除了纳米线原材料的单独处理，减少了潜在的暴露步骤，并有利于直接集成到所需的器件结构中。 智力优点：这项研究基于 PI 实验室的最新发现，即可以在浸没在流体前体环境中的电阻和感应加热金属表面上制造硅和锗纳米线。这种方法提供了研究有关西北生长机制和速率决定步骤的突出基本科学问题的机会。将铜膜上的硅纳米线生长作为模型系统的重点是由于硅纳米线的技术重要性以及推进纳米线加工技术以解决可扩展制造和器件集成方面的突出挑战的前景。主要目标是建立柔性基板上纳米线生长的基本工程原理，并使其能够通过卷对卷工艺进行加工。拟议的研究分为三个主要目标：（i）建立在加热金属薄膜上生长的纳米线的基本生长机制，（ii）了解反应动力学和前体传输现象之间复杂的相互作用，以及（iii）分析、设计和演示集成到卷对卷工艺中的纳米线生长。该工作的创新特征在于应用大块金属箔的电阻和感应加热作为一种精确可编程的激活技术来启动纳米线的生长。反应器系统的快速动态响应为获得对纳米线成核和生长的基本热力学和动力学的新见解提供了机会。将研究加热金属的电流-电压和温度瞬变，作为研究纳米线生长动力学的诊断工具。反应器设计的多功能性可以为促进加热表面纳米结构形成的其他领域的进步奠定基础。更广泛的影响：该项目中的技术可能具有深远的工业适用性以及在医疗应用中的使用。此外，PI 将利用与 K-12 项目的既定联系来开发互动学习模块。高中教师的参与应该能够有效地向下一代科学家和工程师说明纳米制造的机遇和挑战。 PI 将与康奈尔材料研究中心的学习借阅图书馆合作，将该模块免费提供给全国高中科学课程。教育活动将通过创建新的跨学科设计课程，将科学发现融入本科生和研究生课堂；该模块将为学生提供构思、设计和评估新制造工艺和化学产品的可行性所需的技能。