IDR: Molecular engineering of thermal interfaces

IDR：热界面的分子工程

• 批准号: 1134311
• 负责人: Avik Ghosh
• 金额: $ 55.9万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1134311&HistoricalAwards=false
• 关键词: IDR; Molecular; engineering; thermal; interfaces

IDR: Molecular Engineering of Thermal Interfaces 1134311Avik Ghosh, Patrick E. Hopkins & Lloyd R. Harriott Engineering the conduction of heat in solid materials is essential for a wide array of applications, ranging from thermal management of electronics, to power generation, to information technology. Many of these modern systems include materials and structures with characteristic length scales on the order of tens to hundreds of nanometers. At these length scales, the major thermal resistances arise at the interfaces between two materials, leading to thermal properties of nanosystems that are strongly dictated by these solid interfaces. Therefore, it is of utmost importance to develop mechanisms of controlling and tuning the thermal transport across interfaces to be able to accurately manage the thermal properties of nanosystems. To achieve this, this project will explore thermal transport between two solid layers, controlled by properties of organic molecules grown at their interface. Through the interplay between the wide-band, spatially localized molecular vibrons and the narrow-band, spatially delocalized substrate phonons, the project will aim for the systematic and targeted engineering of the composition, morphology and phonon bandstructures of material interfaces at the molecular scale in order to achieve a high degree of tunability of the interfacial thermal conductance. A combined and closely coupled theoretical and experimental study will be launched exploring various classes of self-assembled monolayers (SAMs) of organic molecules as thermal interfacial materials, as a function of variables such as the SAM and substrate quality and material, utilizing self-assembly and most importantly a rich variety of functional chemistry. The thermal transport across the wide array of SAM-based interfaces will be measured with time domain thermoreflectance. The experimental results will be strongly coupled with ab initio modeling efforts utilizing Nonequilibrium Green's Functions formalisms. The science discovered in this project will also be widely applicable to thermal engineering of generic metal and semiconductor interfacial systems.The intellectual merit of this proposed work is in the development of a new understanding of nanoscale interfacial thermal properties. This will prove critical for the atomistic control of heat flow. Through the close synergy between theory and experiment, the study will enhance the understanding of heat flow and dissipation at their most fundamental, microscopic limits, combining atomistic concepts behind molecular heat flow with solid state concepts of bulk heat flow. It will bridge disciplines, materials, and ultimately the boundary between fundamental science and technological applications. Accurate, well benchmarked simulations will address the critical role of band-alignment and chemistry at the solid-molecular interface. Experiments will focus on fabrication of well-defined SAM-based interfacial structures, modifying them through molecular chemistry, characterization and measurement of thermal boundary resistances with a goal towards creating high quality tunable thermal boundaries. The broader impacts of this project include both engineering relevance and education/outreach components. The knowledge gained will introduce a new concept in nanoscale science: thermal interface control and engineering via molecular chemistry. Nanoscale thermal management and control will bring about disruptive changes to science, technology and economics, ranging from superior quality and tailor-made thermal coatings and thermoelectric refrigerators, to better heat management in the multi-billion dollar semiconductor industry. Educational and outreach activities will involve creation of a nano-curriculum at UVa, tutorial creation on the thermalHUB, integration of research and education through thermal transport labs in courses taught by the PIs, conference organization of session on molecular heat transfer with undergraduate involvement, engaging minority undergraduate students for summer projects through the REU program and training middle school teachers for curriculum development utilizing UVA's Center for Diversity in Engineering.

IDR：热界面分子工程 1134311Avik Ghosh、Patrick E. Hopkins 和 Lloyd R. Harriott 工程固体材料中的热传导对于从电子热管理到发电再到信息技术的各种应用至关重要。 许多现代系统都包含特征长度为数十至数百纳米量级的材料和结构。 在这些长度尺度上，主要的热阻出现在两种材料之间的界面处，导致纳米系统的热特性受到这些固体界面的强烈决定。 因此，开发控制和调节跨界面热传输的机制，以便能够准确管理纳米系统的热性能至关重要。 为了实现这一目标，该项目将探索两个固体层之间的热传输，由其界面处生长的有机分子的特性控制。 通过宽带、空间局域分子振动与窄带、空间离域基底声子之间的相互作用，该项目旨在对分子尺度上材料界面的组成、形态和声子能带结构进行系统和有针对性的工程设计。以实现界面热导的高度可调。将启动一项紧密结合的理论和实验研究，探索各种类型的有机分子自组装单层 (SAM) 作为热界面材料，作为 SAM 和基板质量和材料等变量的函数，利用自组装最重要的是丰富多样的功能化学。 跨各种基于 SAM 的接口的热传输将通过时域热反射进行测量。 实验结果将与利用非平衡格林函数形式主义的从头开始建模工作紧密结合。 该项目中发现的科学也将广泛应用于通用金属和半导体界面系统的热工程。这项工作的智力价值在于发展了对纳米级界面热性质的新理解。 这对于热流的原子控制至关重要。通过理论与实验之间的密切协同，该研究将结合分子热流背后的原子概念与体热流的固态概念，增强对热流和耗散在最基本、微观极限下的理解。它将弥合学科、材料，并最终弥合基础科学和技术应用之间的界限。 准确、基准良好的模拟将解决能带排列和化学在固体分子界面的关键作用。 实验将侧重于制造基于 SAM 的明确界面结构，并通过分子化学、热边界电阻的表征和测量对其进行修改，目标是创建高质量的可调节热边界。该项目更广泛的影响包括工程相关性和教育/推广部分。 所获得的知识将引入纳米科学的新概念：通过分子化学进行热界面控制和工程。 纳米级的热管理和控制将为科学、技术和经济带来颠覆性的变化，从卓越的品质和定制的热涂层和热电冰箱，到价值数十亿美元的半导体行业中更好的热管理。教育和外展活动将包括在弗吉尼亚大学创建纳米课程、创建ThermalHUB教程、通过热传输实验室将研究和教育整合到PI教授的课程中、组织本科生参与的分子传热会议、参与通过 REU 项目为少数族裔本科生开展暑期项目，并利用 UVA 工程多样性中心培训中学教师进行课程开发。