The thermoelectric effect refers to the conversion between an electrical potential and a temperature difference. That is, one can either use the effect for ‘solid state’ cooling/heating, or for harvesting electrical energy from an external temperature gradient. The thermoelectric ‘figure of merit’ for a material is called ZT and for the best known thermoelectric alloys it is usually around 1. Graphene is by itself not a great thermoelectric material, but it has previously been shown that when nanostructured, the heat conductivity of graphene is suppressed and the Seebeck coefficient enhanced, such that it may be relevant for nano-sized thermoelectric devices.
Recently, a new type of nano-structured graphene was synthesized - the nanoporous graphene. We have previously investigated this material’s electronic properties, but not the phononic properties nor the Seebeck coefficient. We suspect that due to its unique structure - resembling a series of nanoribbons connected by thin ‘molecular bridges’ - that it could either directly or by modification become a high ZT material.
The aim of this project is to calculate the thermoelectric figure of merit (ZT) for nanoporous graphene. This will require calculation of both electronic and phononic transport properties. We will then investigate possible modifications to the material to further enhance the figure.
Computer simulations using density functional theory (DFT) software. Phonon calculations. Quantum transport using non-equilibrium Greens functions for both electrons and phonons. Programming in Python.
Student should know solid state physics (eg course 10303). Student should be at least superficially experienced with Python. We recommend (but dont require) eg. course 10325.