Collaborative Research: First-Principles Calculations of Phonon Thermal Transport in Bulk and Nanostructured Materials

主要研究者：大卫布洛伊多，1纳塔利奥明戈，2和德里克斯图尔特。3附属机构：1波士顿学院; 2加州大学，圣克鲁斯; 3康奈尔大学。提案标题：合作研究：首先-体相和纳米结构材料中声子热输运的理论计算本研究的目标是发展一种理论方法来描述体相和纳米结构材料中的热输运，原则 这种方法的一个核心特征是它没有可调参数。这将允许声子的热输运和晶格热导率在主机的散装半导体以及在新的纳米系统的研究和理解。待研究的系统包括：块状晶体，如硅、锗和砷化镓;纳米结构系统如量子阱和量子线超晶格，具有显著界面电阻的结构，单层和多层薄膜，目前对绝缘和半导体材料中的热传输进行建模的方法通常基于高度参数化的弛豫-时间近似或纯经典分子动力学计算。严格的第一性原理理论在这里开发没有可调的参数，并充分纳入量子力学声子散射过程。因此，它将提供预测能力，以支持正在进行的和未来的纳米材料热传输实验研究，并有助于开发针对特定应用而设计的新纳米材料。这个为期三年的项目将为一名博士后研究员和一名博士研究生提供培训。此外，本科生将通过波士顿学院和康奈尔大学的NSF本科生研究经验项目参与该项目。 该项目期间开发的计算工具将被集成到一套免费的声子热输运工具中，这些工具将成为康奈尔纳米科学技术设施（CNF）建立的计算库的一部分。这些计算工具将可供任何研究人员使用。该研究计划将有助于开发具有所需热传输性能的新材料。这将促进下一代热电材料、热障涂层材料和热界面材料在热管理方面的技术突破。

Principal Investigators: David Broido,1 Natalio Mingo,2 and Derek Stewart.3Affiliation: 1Boston College; 2University of California, Santa Cruz; 3Cornell University.Proposal Title: Collaborative Research: First-Principles Calculations of Phonon Thermal Transport in Bulk and Nanostructured MaterialsThe research objective of this collaborative effort is to develop a theoretical approach to describe thermal transport through bulk and nanostructured materials from first principles. A central feature of this approach is that it has no adjustable parameters. This will allow the study and understanding of phonon thermal transport and lattice thermal conductivity in a host of bulk semiconductors as well as in novel nanoscale systems. Systems to be investigated include: Bulk crystals such as silicon, germanium and gallium arsenide; nanostructured systems such as quantum well and quantum wire superlattices, structures with significance interface resistance, single and multilayer thin films, defects in nanowires and nanotubes.Intellectual Merit Current approaches to model thermal transport in insulating and semiconducting materials are typically based on either highly parameterized relaxation-time approximations or on purely classical molecular dynamics calculations. The rigorous first principles theory to be developed here has no adjustable parameters and incorporates fully the quantum mechanical phonon scattering processes. It will therefore provide predictive power to support ongoing and future experimental studies of thermal transport in nanomaterials, as well as contributing to the development of new nanomaterials engineered for specific applications. Broader Impacts This three-year project will provide training for one postdoctoral researcher and one doctoral graduate student. In addition, undergraduate students will participate in this project through NSF Research Experience for Undergraduates programs at the Boston College and Cornell sites. Computational tools developed during this project will be integrated into a free set of phonon thermal transport tools that will become part of the computing library established at the Cornell Nanoscale Science and Technology Facility (CNF). These computational tools will be available for use by any researcher. This research program will contribute to the development of new materials with desired thermal transport properties. This will facilitate technological breakthroughs in thermal management for the next generation of thermoelectric materials, thermal barrier coating materials, and thermal interface materials.