Dr. Gregory Auton
Doctoral Prize Fellow: condensed matter physics, solid state physics, materials science
I'm developing energy harvesting devices. A car exhaust, for example, is several hundred degrees and about a third of the petrol energy is lost to the tarmac on the road. We’re trying to build thermal rectifying devices that use waste energy from anything that emits heat. The rectifier is a diode which works at high frequency. It needs to be made of a material with really high mobility, where the electrons really shift. In a material like gold an electron won't move very far before it hits something like an atom or a vibration in the lattice. But graphene is actually the highest mobility material, at room temperature, that we know of. There are just no defects in graphene like there is in gold or platinum or silver so the electrons virtually fly for say, 30 micrometres before they scatter. It's a long way.
I spend a lot of my time making graphene flakes. We get big pieces of high quality graphite and then stick pieces of it onto a special tape, peel it off, and repeat the process until it's thin enough to put onto a wafer. But we’re not just producing graphene, there’s a whole range of different 2D materials we've discovered we can exfoliate. Graphene opened the gates to these; materials like boron nitride, tungsten disulphide, molybdenum disulphide and molybdenum diselenide. There’s a whole zoo of them. In fact, there's a paper called The Two-Dimensional Zoo. What’s interesting is the way these new materials behave when combined. This introduces new physics.