CAREER: First Principles-Enabled Prediction of Thermal Conductivity and Radiative Properties of Solids

职业：利用第一原理预测固体的热导率和辐射特性

• 批准号: 1150948
• 负责人: Xiulin Ruan
• 金额: $ 40万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1150948&HistoricalAwards=false
• 关键词: CAREER; First; Principles; Enabled; Prediction

PI: Xiulin Ruan, Purdue UniversityProposal Number: CBET-1150948The proposed effort will enable the prediction of thermal conductive and radiative properties of solids from first principles. Thermal conductivity and far-infrared thermal radiative properties of solids are critical issues in many modern and emerging applications such as thermal management, electronics, photovoltaics, and thermoelectrics. Both properties, although seemingly unrelated, are governed in the atomic scale by the dispersion relation and relaxation time of the same thermal energy carrier called phonon. To guide the design and synthesis of these materials, it is highly desirable to predict their thermal properties from first principles, i.e., from their atomic structures without the use of adjustable parameters. However, existing classical interatomic potentials are inaccurate even for standard materials such as silicon and carbon since the potentials were not intended for the purpose of thermal transport modeling. For most other solids, the classical potentials haven't been developed yet, making the prediction of their thermal transport properties impossible. Therefore, it is the objective of this proposal to formulate new methodologies that can develop accurate interatomic potentials or can completely bypass the use of classical potentials, for thermal property prediction. Toward this goal, two multiscale multiphysics methods will be developed in parallel. In the first method, first principles calculations will be used to develop accurate classical interatomic potentials that are intentionally optimized for thermal transport modeling, and the potentials will then be employed in classical MD to predict thermal conductivity. In order to bypass the challenging and tedious potential development process, the second method will introduce a new tight-binding molecular dynamics (TBMD) method to produce the trajectory of atoms, which will then be used in phonon spectral analysis to obtain spectral phonon relaxation time as well as thermal conductivity and radiative properties. The predictive power will be demonstrated first on standard materials such as silicon, and then on a range of important but complex thermoelectric and photovoltaic materials, including Bi2Te3 and GaAs bulk and nanomaterials.The intellectual merit of the proposal centers around fundamentally new prediction methods based on first principles for both thermal conductive and radiative properties. The tight binding MD together with phonon spectral analysis will revolutionize thermal transport property prediction of a wide range of materials of technological importance, on which atomic scale prediction was not possible before due to the lack of empirical interatomic potentials. The methods will also be used on practically important thermoelectric and photovoltaic nanomaterials, including Bi2Te3 and GaAs, for the first time to guide experimental synthesis.The research effort will impact thermal science and education/outreach programs. The new prediction methods will be of broad interest due to their generality. Important applications, including thermal management, thermoelectrics, electronics, and photovoltaics will benefit from the new insights generated using these methods. Under-represented and undergraduate students will continue to be involved in research. A key education/outreach component would be the dissemination of the research and education codes resulted from this project to nanoHUB and thermalHUB for general public use. Comprehensive documentation, online lectures, and tutorials explaining the codes will be provided. These materials will be of wide interest in the PI's field given the new capabilities they provide.

主要研究者：Xiulin Ruan，Purdue University提案编号：CBET-1150948所提出的努力将能够从第一原理预测固体的导热和辐射性质。固体的热导率和远红外热辐射性质在许多现代和新兴应用中是关键问题，例如热管理、电子学、光电子学和热电学。这两种性质，虽然看起来不相关，但在原子尺度上由称为声子的同一热能载体的色散关系和弛豫时间决定。为了指导这些材料的设计和合成，非常希望从第一原理预测它们的热性质，即，从它们的原子结构中分离出来而不需要使用可调参数。然而，现有的经典原子间势是不准确的，即使是标准的材料，如硅和碳，因为电位不打算用于热输运建模的目的。对于大多数其他固体，经典势还没有被开发出来，使得预测它们的热输运性质是不可能的。因此，这是本提案的目的，制定新的方法，可以开发准确的原子间势，或可以完全绕过使用经典的潜力，热性能预测。为了实现这一目标，两个多尺度多物理场方法将并行开发。在第一种方法中，第一原理计算将用于开发精确的经典原子间势，这些势被有意地优化用于热输运建模，然后将在经典MD中采用这些势来预测热导率。为了绕过具有挑战性和繁琐的潜在开发过程，第二种方法将引入一种新的紧束缚分子动力学（TBMD）方法来产生原子的轨道，然后将其用于声子谱分析，以获得光谱声子弛豫时间以及热导率和辐射特性。预测能力将首先在硅等标准材料上得到验证，然后在一系列重要但复杂的热电和光伏材料上得到验证，包括Bi 2 Te 3和GaAs块体材料和纳米材料。该提案的智力价值集中在基于导热和辐射特性第一性原理的全新预测方法上。紧密结合的分子动力学与声子谱分析将彻底改变广泛的技术重要性，在原子尺度上的预测是不可能的，由于缺乏经验的原子间相互作用势的材料的热输运性质的预测。该方法还将首次用于实际重要的热电和光伏纳米材料，包括Bi 2 Te 3和GaAs，以指导实验合成。研究工作将影响热科学和教育/推广计划。新的预测方法将广泛的兴趣，由于其通用性。重要的应用，包括热管理，热电，电子和光电将受益于使用这些方法产生的新见解。代表性不足和本科生将继续参与研究。一个关键的教育/外联组成部分将是向nanoHUB和thermalHUB传播该项目产生的研究和教育代码，供公众使用。将提供全面的文档、在线讲座和解释代码的教程。这些材料将在PI的领域给予广泛的兴趣，因为它们提供了新的能力。