Investigation of new semiconductor materials for wide band-gap devices

This project aims to develop new and enhanced wide band-gap semiconductor alloys, with a view to application in improved devices. In particular, we are targetting ultra-violet (UV) emitters, including those in the deep UV wavelength ranges where there are important applications in water purification and sterilsation, as well as high-frequency high-power transistors. We will work closely with crystal growth specialists, in particular colleagues at Nottingham University, Nagoya University, Nanjing University and CNRS-CRHEA in France. Material produced by epitaxial techniques, such as molecular beam epitaxy, will be characterised by the student using advanced techniques that investigate material composition, structure and optical properties at a sub-micron length scale. It is closely connected to an EPSRC Strategic Equipment Award which provided a new £1M field-emission gun electron probe micro-analyser (FEG-EPMA) and low-voltage scanning electron microscope, which are configured for highly spatially resolved x-ray microanalysis and cathodoluminescence studies of semiconductors. One target
material is the alloy aluminium gallium nitride (AlGaN) which has attractive properties for the UV energy range. The project will experimentally test the theoretical predictions of material properties and aim to demonstrate the quality of AlGaN layers fabricated in a range of crystal orientations and with a range of doping. This will open the way to producing more effective, more compact and more efficient devices in the UV range.