Heat transport in solids from first principles.
Speaker: Peter Bobbert (CCER)
Time: Nov. 15, 2018, 10:00–11:00
Location: TU/e, Cascade, room 2.10
Fundamental understanding of heat transport in solids is crucial for optimization of energy-related applications like thermo-electricity and heat storage. Heat transport in metals and semiconductors is dominated by electrons and phonons, respectively. The thermal conductance in metals is very closely linked to the electrical conductance, so that optimization of heat transport amounts to optimization of electrical transport. The understanding of heat transport in semiconductors is far less developed and first-principles methods to calculate the phonon-mediated thermal conductance of semiconductors have only rather recently been developed. I will discuss how the thermal conductance of bulk semiconductors as well as semiconductor nanowires can be calculated by the classical Kubo-Green method as well as by solving the quantum-mechanical phonon Boltzmann equation. For the case of heat flow through nanowires connecting two thermal reservoirs I will also discuss the application of the Landauer approach. We will encounter fascinating phenomena like hydrodynamic heat flow, ballistic phonons, and phonon localization.