D. Phil Projects October 2012

1. Quantum transport in graphene and carbon nanostructures

Carbon nanotubes and graphene (Nobel Prize 2010) are revolutionising the study of semiconductors and offer the potential for a new generation of devices which may supplant silicon. This project aims to study the electrical properties of graphene and carbon nanostructures in high magnetic fields where the electrical conduction is strongly influenced by quantum effects giving rise to phenomena such the Quantum Hall Effect and Coulomb Blockade. By studying nanostructures which are typically only a few nanometers in size the energy levels and transport can be controlled and modified to create new properties and behaviour.  The structures to be studied will be made using a recently installed next generation electron beam lithography system capable of writing features down to a size of 20nm and it is planned to experiment with combining these with carbon nanotubes also.

2. Carbon based PhotoVoltaic Devices

Finding new ways to produce Photovoltaic (PV) cells with high efficiencies and novel manufacturing techniques is a challenge for semiconductor physics. This project will explore the use of graphite, carbon nanotubes and polymer semiconductors to produce new structures which can act as PV devices with responses in both the visible and infrared part of the spectrum. The project will combine optical spectroscopy of carbon nanotube/polymer nanostructures with studies of electrical properties and fabrication techniques.

The experiments will use techniques such as PhotoLuminescence Excitation (PLE) spectroscopy to study the transfer of energy and charge through different components of the cells and infrared spectroscopy to examine the behaviour of transparent conducting layers such as graphene and nanotubes. These techniques will be combined with electroluminescence and photoresponse to evaluate the potential efficiency of the devices.