Postgraduate Studentship: Low temperature diamond thermionics for solar power applications
Joint DTA award between Physics & Chemistry, 3.5 years PhD, starting October 2012.
Prof Paul W May, Dr Neil A Fox
Current solar power devices use photovoltaic devices to convert sunlight into electricity. However,
another possible route is to use the heat from the sun, which can be collected using a parabolic
reflector and focused onto a thermionic emitting material. When hot, such a material emits electrons
which can be collected and utilised as electric power. Thermionic energy conversion offers the
possibility of greatly increasing the energy that can be harvested from the sun, and may go a long way
towards making solar power viable – even in the UK.
To make this work, we require a thermionic material that emits electrons efficiently at low
temperatures (500°C) rather than 1000-2000°C for conventional metals. Recent discoveries at Bristol
have shown that diamond surfaces treated with LiO (and other layers) have the ideal properties to
make viable thermionic emitters. As such, diamond thin films and nanoparticle composites are being
produced and studied by the Diamond Group in Bristol for applications in concentrated solar thermal
power, as well as high-brightness electron sources and nuclear batteries. We now seek a PhD student
to continue this work. The funding is 50% Physics and 50% Chemistry (DTA awards) and will be for
3.5 years, with a stipend the same as a standard Research Council grant. The candidate should have
or expect to achieve a 1st Class (or high Upper Second Class) Honours MSci degree (or equivalent) in
a suitable subject (Physics, Chemistry, Chemical Physics, Materials, etc).
The successful applicant will undertake a programme of investigations that seek to increase our
understanding of the mechanism of thermionic carrier production and emission in diamond thin films.
This will be achieved by the synthesis, characterisation and modelling of diamond materials and
metal-diamond composites with different bulk and surface electrical properties. Modelling will be
performed using the DFT models hosted on the Blue Crystal computing facility at Bristol. Synthesis
and surface treatment of thin film and nanoparticle diamond composites will be performed in the
Diamond Lab (School of Chemistry) using hot filament and microwave chemical vapour deposition
reactors and pulsed laser systems. Thermionic and field emission testing will be conducted in a
purpose-built test chamber also located in the diamond lab. The student will also be trained in the use
of material preparation and characterisation tools located in the School of Physics (TEM, Low
temperature Raman PL, Balzers sputterer, O2-plasma etcher), Interface Analysis Centre (Focused Ion
Beam, Secondary Ion Mass Spectroscopy) and the Bristol Centre for Nano Science and Quantum
Information (UHV SPM surface analysis).
Interested applicants must be from the UK (or EU and been resident in the UK for >3 years) and
should contact either paul.may@bris.ac.uk or neil.fox@bris.ac.uk for more details.
Diamond group web page: http://www.chm.bris.ac.uk/pt/diamond/