Thermal Transport

Thermal transport in semiconductor nanostructures

The scaling of semiconductor devices also changed the way heat flows through these systems. Heat flows in semiconductors predominantly in the form of lattice vibrations also called `phonons'. The shrinking the devices shift the heat transfer from the particle nature to the wave nature and to investigate heat flow in such a regime requires new tools. The following ingredients have been developed for the investigating heat flow at nano-scale:

  • Phonon model: To capture the lattice dynamics within harmonic limit a good phonon model is needed. Our phonon model is an extension and combination of the older Keating's VFF model and Junger's VFF model. We call it the Modified VFF model (Link to JCE paper).

Phonon model:

  • Landauer's model This allows to capture the heat flow processes in uniform nanostructures like nanowires, UTBs, etc., under small temperature differences.

Landauer's model

  • Phonon Green's function heat solver To understand the flow of heat is to understand the flow of phonons. Within the wave function formalism the phonon transport is solved to understand the thermal transport in rough nanowires, superlattice nanowires, etc.

Phonon Green's function heat solver

  • Thermal transport in SiGe superlattice nanowires Understand phonon transport in SiGe superlattice(SL) nanowire. Reduce lattice thermal conductivity by using different structures of nanowire

Phonon Green's function heat solver

 

 

Group member involved:

  • Abhijeet Paul: Phonons, thermal transport in nanowires using landauer's principle and Green's function, thermal boundary resistance
  • Mathieu Luisier: Phonons, Green's function solution to thermal transport.
  • Kai Miao : Thermal transport in SiGe superlattice nanowires, Thermal rectification.

Associated publications