Efficient Conversion of Heat Waste into Electrical Power with Self-Assembled Organic Thermoelectric Junctions

The University of Bath is inviting applications for the following PhD project under the supervision of Prof Alain Nogaret in the Department of Physics and Dr Dan Pantos in the Department of Chemistry.

Overview of the Project:

Heat is generated as a by-product of many industrial processes, data processing centres, and living organisms. Some studies estimate that 66% of industrial energy consumption worldwide is discharged as low-grade heat (T<200°C). Data processing centres power the internet with tens of thousands of IT devices consuming in excess of 100 MW per site most of which is ultimately wasted as heat. The ten-fold increase in internet traffic over the past 8 years, and the 11% average year-on-year increase in the number of servers has led to an unsustainable increase in power consumption and associated CO₂ emission. There is thus an urgent need for efficient and scalable thermoelectric devices capable of recovering low-grade heat and converting it back into clean electricity. Thermoelectric devices have vocation to meet another important need in bioelectronic medicine by scavenging heat from the human body to grant unlimited power autonomy to wearable sensors in remote health monitoring and implants such as cardiac pacemakers.

This project will develop a novel class of materials intercalating graphene and self-assembled polyaromatic molecules to achieve unprecedented ZT figures of merit for thermal conversion efficiency. We anticipate a ZT factor of 560 for our device concept compared to 2.4 for Ruddlesden-Popper oxides which are some of the best thermoelectric materials available. Our devices exploit the high Seebeck coefficient of pristine graphene, high electrical conductivity and the absence of phonon scattering to achieve a high base ZT value. The novelty of our approach is to increase the base ZT value by functionalising graphene ribbons with both electron rich (perylene) and electron poor molecules (naphthalene diimide) to achieve n-type or p-type doped graphene. This has the following advantages:

• The electronegativity/positivity of the adsorbed molecules controls the polarity of the thermovoltage.
• Perylene and naphthalene diimide molecules self-organise into organic monolayers with quasi-crystalline packing on graphene. They also form ion-dipole bonds out of the plane which will be used clip the n-type and p-type graphene ribbons end-to-end to form the thermoelectric device.
• The functionalization of graphene will increase its electrical conductivity through doping and decrease its thermal conductivity by reducing the symmetry of the graphene lattice. Both effects conspire to increase the thermoelectric conversion efficiency  from 0.1 in pristine graphene to 560 in our device concept.

Project keywords: Quantum transport, molecular electronics, thermoelectrics, energy materials.

Candidate Requirements:

Applicants should hold, or expect to receive, a First Class or good Upper Second Class Honours degree (or the equivalent) in Physics, Natural Sciences of Materials Sciences. A master’s level qualification would also be advantageous.

Non-UK applicants must meet our English language entry requirement.

Enquiries and Applications:

Informal enquiries are welcomed and should be directed to Prof Alain Nogaret (email [Email Address Removed]).

Formal applications should be made via the University of Bath’s online application form for a PhD in Physics.

More information about applying for a PhD at Bath may be found on our website.

Equality, Diversity and Inclusion:

We value a diverse research environment and aim to be an inclusive university, where difference is celebrated and respected. We welcome and encourage applications from under-represented groups.

If you have circumstances that you feel we should be aware of that have affected your educational attainment, then please feel free to tell us about it in your application form. The best way to do this is a short paragraph at the end of your personal statement.