Thermal transport in simulated nanostructures

Abstract

Nanostructures are a critical topic for the research of heat transport as they are frequently used in devices where either temperature control or dissipation are critical. At such small scales, the behaviour of heat transport can be quite distinct from classically familiar modes. In this work, the effects of geometry and scale on nanostructures is investigated through various simulation methods. A particular focus is non-diffusive heat transport and angled geometries, and their interplay. It is seen that complex and angled geometries result in increased thermal resistance, but that this general result can be dependent on the particularities of geometry. Effects such as lattice orientation can cause a reduction of thermal resistance when the alignment is properly chosen. An emphasis is placed on the complexity of heat transport at the nanoscale and its similarities to other models of physical transport, such as radiative and geometrical optics. The variety of these models are reflected in the variety of simulation methods used: molecular dynamics, phonon Monte Carlo, Lattice Boltzmann Methods, classical heat equation solutions and, briefly, reflective ray optics. Discussion is carried out on the implications of a more ballistic and radiative transport scenario than is typically expected in nanoscale situations, and future prospects and consequences are suggested in turn.