PhD Scholarship: Multi-Junction Silicon Photodiodes for Biomedical Applications

The School of Photovoltaic & Renewable Energy Engineering (SPREE) within the UNSW Faculty of Engineering has been at the leading edge of global solar cell development for over 30 years, reporting many world record solar cell efficiencies. In a collaboration with UNSW Graduate School of Biomedical Engineering we are now aiming to develop photodiodes that can stimulate nervous tissue upon illumination and to fabricate an array of small photodiodes with similar functionality as a traditional electrically powered electrode array.

Typically, electrodes in brain machine interfaces require voltages that are higher than the obtainable voltage of a single mono-crystalline silicon photodiode. This project aims to stack multiple silicon photodiodes to overcome this limitation. While one approach is to epitaxially grow a stack of photodiodes, we will also look into fabricating conventional photodiodes via furnace diffusion or ion-implantation and then stacking them via wafer bonding. For this project we are looking for outstanding PhD candidates who are interested in the areas of:

• Fabrication, characterisation and device simulation of silicon based tunnel-junctions
• Development of waferbonding processes and characterising bonded interfaces
• Optimisation and tailoring of silicon device fabrication processes like high aspect ratio etching, photolithography, etc

While the motivation for the project is a biomedical application, the working area will be in silicon device fabrication. The supervisory team will consist of Dr Udo Römer and A./Prof. Nicholas Ekins-Daukes. We will provide high-quality training for conducting scientific experiments and will ensure that our students develop a good understanding of semiconductor device physics. The project is suitable for applicants with a first degree in science or engineering. Since we are developing novel devices with challenging processing tasks, we are looking for practically orientated students that are not only keen to learn a range of fabrication and characterisation techniques, but are also motivated to find creative solutions to overcome unforeseen problems.

Please contact Dr Udo Römer (u.romer@unsw.edu.au) for further information. For your application please also attach the following documents: CV, academic transcript, outcome of UNSW HDR self-assessment (https://selfassessment.research.unsw.edu.au).

For more information and further vacancies, please also look at our group's website: https://www.qpvgroup.org/vacancies