I have no advertised postdoctoral positions available at present.
You are also welcome to get in touch if you are thinking of making an application for external funding (e.g. Newton Fellowship, Marie Curie etc) to work as a postdoctoral researcher in my research area. Please send a CV.
I am always interested in hear from suitably-qualified potential PhD students, with an interest in electronic materials and interfaces for a range of energy applications. Please read the information below and make an enquiry by e-mail (john dot d dot murphy at warwick dot ac dot uk). Please make sure to attach a CV. Please note that I will require you to make a formal application before I can make a final admissions decision. Funding may be available for suitably-qualified UK/ EU students. I typically find suitable graduate students have undergraduate degrees in Physics, Materials Science, Chemistry or Electronic Engineering. Some available projects include:
1. PhD project: Multi-functional thin films for photovoltaic and battery storage applications
More than 90% of photovoltaic solar cells are made from crystalline silicon. Record-breaking silicon solar cells have efficiencies in excess of 26%, and such cells require silicon substrates in which photogenerated charge carrier diffusion lengths exceed 1 mm. As substrates are typically < 200 µm thick, the properties of the cell are strongly influenced by charge carrier recombination at surfaces. In Warwick, we have recently developed a novel ionic surface passivation scheme which can passivate surfaces extremely well (see open access papers at https://dx.doi.org/10.1109/JPHOTOV.2017.2751511 and https://doi.org/10.1016/j.solmat.2018.03.028). This has enabled us to exceed the so-called “intrinsic limit” of carrier lifetime in silicon, which implies that the current limit of a silicon cell efficiency is slightly conservative. We anticipate the films we have developed will have other uses, including in tandem photovoltaic structures and in the context of surface treatment of silicon anodes for lithium ion batteries, which have the potential to provide an order of magnitude capacity improvement compared to graphitic carbon.
The aim of this PhD project is to develop ultra-thin passivation films (< 1 nm) derived from ionic solutions, and atomic layer deposition (ALD) methods, which exhibit excellent thermal and electrical stability when applied to semiconductor surfaces. Central to the project is Warwick’s new £400k ALD facility which was commissioned in the Science City Cleanroom in early 2018. The objective will be to develop a fundamental understanding of the passivation mechanism at the atomic scale and how processes can be manipulated in order to achieve optimal long-term thermal and electrical properties. The films developed will then be applied in a range of contexts, including silicon photovoltaics, next-generation photovoltaic architectures such as silicon-based tandems, and lithium ion battery anodes. The student will gain experience with cleanroom processing, and cutting-edge materials characterisation by electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and nuclear magnetic resonance. In addition, the student will use silicon-specific analytical techniques available in Dr Murphy’s laboratory in Engineering. This includes minority carrier lifetime measurements, and photoluminescence imaging. The project would suit someone with a materials science, chemistry, physics or electrical engineering background. Dr Murphy leads the multi-institution EPSRC SuperSilicon PV project (EP/M024911/1) and there will be opportunities for collaboration with other universities in the UK and internationally.
2. PhD project: silicon materials for high efficiency photovoltaic solar cells
The performance of the very highest efficiency silicon solar cells (e.g. back-junction back-contact cells) is becoming limited by the minority carrier lifetime in the substrate. Although carrier lifetimes in the best silicon wafers now routinely exceed 1ms, the best cells will soon require lifetimes of > 10ms. Although in normal operating conditions such lifetimes are physically possible, defects in the material mean that they are seldom achieved in practice. Recombination centres present in very low concentrations (parts in a million million) can impinge on the carrier lifetime. This project aims to understand the origin of this weak recombination activity, and ideally developing ways to overcome it. Experimental techniques such as photoconductance lifetime measurements and photoluminescence imaging will be used, and there will be a need for occasional cleanroom working. The project will be in collaboration with a leading silicon manufacturer. This PhD project requires prior knowledge and an interest in semiconductor materials. It would ideally suit a candidate with an undergraduate degree in physics, materials science, or electrical engineering.
3. Other projects
If you are interested in PhD projects in my research area then please contact me.
Funding for PhD students (UK and the rest of the EU)
Studentships for UK and EU applicants may be available via the EPSRC DTA or similar schemes. These are usually subject to internal competition schemes, but strong candidate should not be deterred.
Funding for PhD students (outside of the EU)
I am happy to receive applications from students from outside the EU, but it is very difficult for me to find financial support. Very strong non-EU students without their own funding could consider submitting an application for a Warwick Chancellor's International Scholarship, for which the deadline is also usually in January. Please note that this scheme is exceptionally competitive. If you have your own financial support (e.g. personal funds or a scholarship from your home country) then please get in touch.
Internships/ summer projects
I am interested to hear from Warwick undergraduates from Engineering or Physics who might be interested in performing summer projects in my laboratory. Warwick undergraduates can apply for funding for summer projects from the Undergraduate Research Support Scheme (URSS). Additional schemes are often run by the Materials GRP or the Energy GRP. Deadlines for these schemes are usually in January/ February, so please contact me at least a couple of weeks before the deadline to discuss possible opportunities.
I receive a lot of enquiries from overseas undergraduate/ masters students wanting to carry out internships/ summer projects in my laboratory. Unfortunately, I do not usually have the resources to support such projects at present. I can only therefore consider applications for short visiting projects if the student already has experience directly relevant to my research area.