Thermal Engineering Lab

Vanderbilt University
"research in ...
thermal measurement
      and energy transport"

Research Highlight

Previous highlights are archived.
April 29, 2011
coupled NEGF transport
Research is currently underway to investigate the dissipative transport in Si/Ge superlattices using a novel coupling approach that incoperates both a non-equilibrium Green's function (NEGF) phonon model and a NEGF electron model. The scattering rate of a 7nm semicondutor device with alternating 1nm Si and Ge layers is shown in the figure. The inset figure depicts the conduction band edges and the associated local density of states (LDOS) spatially throughout the structure. It is suggested by the increase in the scattering rate near 0.17eV that phonon assisted tunneling lead to increased transport of superlattice structures enhancing the thermoelectric properties.

About TELab

The Thermal Engineering Lab is directed by Prof. Greg Walker of the Department of Mechanical Engineering at Vanderbilt University. Our mission is to explore the physical effects of energy transport particularly in nanoscale structures to obtain a better understanding of the physical world that can lead to engineering discoveries in energy applications.

One focus is in microscale energy transport in semiconductor devices designed for energy conversion. This includes thermoelectric devices, solar cells, and fuel cells, for example. We also study fundamental artifacts of small scale transport such as thermal rectification, interfacial conductance and nanofluid convection.

A second focus area is in heat flux measurement using thermographic phosphors and ultrasonic approaches. Our techniques have been applied to gun barrels, aerospace testing in wind tunnels and combustion chambers.

Prospective students

We are always looking for quality students to join our group. Prospective students should contact Greg Walker for information about upcoming projects.

Copyright 2008 Vanderbilt University