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

半导体纳米线（NW）是许多新兴纳米技术的基本构件。纳米线的技术影响范围从能源技术，光电子学，以及在纳米和生物技术的交叉点出现的新应用。在能量存储技术的情况下，硅纳米线（Si NW）呈现出用于高容量锂离子电池（LIB）的最有吸引力的电极材料之一。硅纳米线也有望在新兴的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，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的组成（例如GaN、CdS和CdSe），多色发光二极管（LED）已经成为可能，用于紫外、可见和近红外发射。 对NW表面功能化的精确控制使得能够制造基于NW的化学和生物传感器，包括癌症标志物的多重电检测和单一病毒的检测。垂直Si NW电极阵列也已被证明是一个有前途的平台，与神经细胞的接口，使神经假体和研究的神经元电路在体内。为了满足NW原型的快速进展所产生的日益增长的期望，该领域的注意力正在转向可扩展和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：用于电动车辆的85kWh电池将需要约40kg的Si NW用于阳极。本提案中介绍的制造NW器件的方法旨在推进这一目标。除了NW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。由于其小尺寸和高迁移率，纳米线和纳米管引起了人们对石棉效应的关注。该项目开发的NW加工技术直接在集电器金属上生长NW;这消除了NW原材料的单独加工，减轻了潜在的暴露步骤，并有利于直接集成到所需的器件结构中。智力优势：拟议的研究是基于PI实验室最近的发现，即Si和Ge NW可以在浸没在流体前体环境中的电磁和感应加热的金属表面上制造。这种方法提供了一个机会，研究突出的基础科学问题的机制和速度决定步骤的NW增长。硅纳米线的技术重要性和先进的纳米线加工技术，以解决突出的挑战，可扩展的制造和设备集成的前景的动机，重点放在硅纳米线生长在铜膜作为一个模型系统。主要目标是建立在柔性衬底上生长NW的基本工程原理，并通过卷对卷工艺进行处理。拟议的研究结构沿着三个主要目标：（一）建立加热的金属薄膜上生长的纳米线的基本生长机制，（二）了解反应动力学和前体传输现象之间的复杂相互作用和（iii）分析，设计和演示集成到一个卷到卷的过程中的纳米线的生长。所提出的工作的创新特点是在应用电阻和感应加热的散装金属箔作为一个精确的可编程激活技术，启动NW的增长。反应器系统的快速动态响应提供了一个机会，以获得新的见解的基本热力学和动力学的NW成核和生长。的电流-电压和温度瞬变的加热金属将作为一种诊断工具，研究NW增长的动力学进行调查。反应器设计的多功能性可以为促进在加热表面形成纳米结构的其他领域的进步提供基础。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计划建立的联系来开发互动学习模块。高中教师的参与应该在说明纳米制造的机会和挑战下一代的科学家和工程师的影响。PI将与康奈尔材料研究中心的学习借阅图书馆合作，使该模块免费用于全国高中科学课程。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可行性所需的技能。

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.