More than 65% of the energy we consume goes into waste heat -- that is, 2/3 of the energy we make by burning dirty fossil fuels literally goes “out the window.” There are many ways in which we can improve upon this massive inefficiency. Our group is interested in exploring how materials can play a role in reducing the waste heat of our cars, appliances, computers, power plants, and well, just about everything we pour energy into. One exciting way to do this is to take the heat and convert it back into electricity, which can be done with thermoelectrics.

Thermoelectric materials offer the possibility of direct conversion of heat into electricity.  A generic thermoelectric circuit is shown in this figure, in which n- and p- type carriers electrically connected to a hot bath (heat sourc

e) and a cold bath (heat sink) flow from hot to cold.  The efficiency with which a material can convert heat into electricity is given by its so-called “figure of merit”, which is currently about 1 for commercially-available materials. Unfortunately, we are quite a ways off: in order to achieve comparable efficiency to that in a typical fossil fuel power plant at typical operating temperatures, i.e. 50% of ideal (Carnot) efficiency, a thermoelectric material with Z = 3 is required.

Recently, new thermoelectric materials have been found with higher figures of merit, but unfortunately these are quite exotic or at the very least expensive and not scalable in a manner that could impact the global energy problem. Thus, as is the case for solar energy conversion, materials for thermal energy conversion need to be discovered that are efficient, abundant, inexpensive, and scalable. This is, again, where computation can play a critical role.

Below are links to descriptions of research directions involving thermoelectrics in our group.

Nanostructured (porous) Thermoelectrics

Density of States Engineering for Thermoelectrics