EPSRC CDT in Metamaterials: Nanoscale patterning of interfaces for thermoelectrics

The studentship is part of the EPSRC Centre of Doctoral Training in Metamaterials (XM2). Its aim is to undertake world-leading research, while training scientists and engineers with the relevant research skills and knowledge, and professional attributes for industry and academia.

The ideal thermoelectric material acts as a glass to phonons and a crystal to electrons. By patterning the structure of the interface, it is intended to manipulate both these properties to make a much higher efficiency thermoelectric than currently known. The patterning, in principle, increases the number of dangling bonds and increases the intermixing of atomic species at the interface, both of which act as phonon scatterers, thus reducing the thermal conductivity. Simultaneously, these dangling bonds effectively provide doping thereby increasing the electrical conductivity of the material. Finally, the structure two constituents layers allow one to adjust the group velocities and allowed frequencies of the two carriers.

The initial focus of the project would be on the power factor. Using first principles theory and empirical models, the Seeback coefficient and the electrical conductivity will be evaluated. The goal will be to study whether the patterned structure results in an improved power factor compared to the unpatterned. Once the fundamental principles are understood, the system of PbTe/PbSe would be explored.

This project fits into the nanomaterials and nanocomposits theme. The student would work in direct collaboration with Deregallera’s material development department and will be in regular contact with Dr. Curran who leads the thermoelectric projects. It is expected that when the magnitude of improvement in the efficiency of the thermoelectrics is known, that Deregallera will head up physical development of these systems.

This project will benefit hugely from the community aspect of the CDT, where acoustic patterned devices as well as other metamaterial devices which are currently in development. The cross pollination between this and other projects would be hugely beneficial to everyone.