Nanoscale Phonon Thermal Transport: Insights and Predictions

Abstract

The management of heat and the understanding of heat transfer are ubiquitous challenges in numerous sciences and technologies, from models of Earth’s thermal history to managing local hot spots in microelectronics. Computational materials physics is now playing an increasingly important role in developing fundamental insights into the lattice thermal conductivity of solids, a fundamentally important parameter that determines the utility of a material for energy-related applications including thermoelectricity, nuclear power generation, heat dissipation and manipulation, and thermal analogs to electronic components (e.g., thermal diodes and switches). Here I will discuss a powerful, predictive method for modeling heat transfer: first principles Peierls-Boltzmann transport. Discussion will focus on application of this method to examine lattice dynamics and transport in a variety of nanoscale systems (e.g., wires, two-dimensional (2D) sheets and layered materials) – comparing with their bulk counterparts and relevant experimental research. In particular I will present recent work related to strain, defects and chemical functionalization in 2D systems, and recent physical insights from neutron scattering in CuCl. Further, I will discuss the role of some extrinsic phonon scattering mechanisms in relation to intrinsic thermal resistance for engineering thermal transport properties in nanoscale materials. L. L. acknowledges support from the Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division for work done at ORNL.