Nanopatterned substrates for epitaxial regrowth

Project:

Semiconductors are at the heart of many optoelectronic and electronic components and extensive research over the past 50 years has seen the performance of devices increase to create the technology-centred world that we see today. Underpinning this increase is the improving quality of the materials in terms of crystal perfection and control of the doping and constituent alloys.

A recent development is the use of semiconductor nanowires for which the ultra-small dimensions allow crystals to have no dislocations or extended defects that can reduce the device efficiency and the unique geometries allow for novel device architectures. Applications include: single-photon emitters, integrated photonic circuits, piezoelectric nanogenerators, photon-triggered transistors and biological sensors.

There are numerous ways to create nanowires, but many produce random arrays that are difficult to integrate into a device. A better way is to seed the growth of nanowires in controlled locations via nanopatterned substrates. Achieving seeding sites of the correct size, crystalline perfection, materials and at a large enough scale is critical to growing high quality homogenous arrays of nanowires with tailored properties. Existing methods to do this either lack resolution or scalability.

At the University of Bath, we have a suite of nanofabrication tools within an established and comprehensive cleanroom. In particular, we have a specialist system for the large area patterning of nanostructures; the only one in the UK and one of a handful globally. Our recent research has explored and extended this system’s capabilities and as a result we are collaborating with a number of research organisations globally who are using our nanopatterned substrates for their research. Nevertheless, further research is required to extend its reach and to tailor its capability to the specific requirements of the nanowire community.

In this experimental project you will become proficient in micro and nanofabrication processes and complementary nanocharacterisation techniques. You will collaborate closely with other institutions within the UK and beyond in order to understand their needs and tailor the processes accordingly.

You will join the wide band-gap semiconductor research group at the University of Bath which has been active in the field of Nitride Semiconductors for over 20 years and has recently specialised in creating group III-N semiconductor nanowires for improved optical emission in the visible and UV. It has the facilities for the growth, fabrication and characterisation of optoelectronic devices based on the group III nitrides, such as gallium nitride, aluminium nitride and indium nitride. In particular, it has extensive experience of incorporating nanostructures into the growth and fabrication processes through advanced nanolithography techniques. Currently, it has active research projects in core-shell nanowire LEDs, site-controlled quantum dots and nanofabrication process development.

Application:

Successful applicants will ideally have graduated (or be due to graduate) with an undergraduate Masters first class degree and/or MSc distinction (or equivalent). Any English language requirements must be met at the deadline for applications.

Informal enquiries: Dr Philip Shields, email [Email Address Removed]

Please ensure that you state the full project title and lead supervisor name on the application form for a PhD in Electronic & Electrical Engineering.

https://samis.bath.ac.uk/urd/sits.urd/run/siw_ipp_lgn.login?process=siw_ipp_app&code1=RDUEE-FP01&code2=0014

Anticipated start date: January 2020