Urgent efforts are required to reduce the cost of renewable energy in order to tackle the worst effects of climate change. The fastest growing renewable energy technology is photovoltaics (PV), which will account for 30% of global power generation capacity in the coming decades. Silicon PV, which currently accounts for more than 90% of the market, is a proven technology where significant technological improvements will ensure further price reductions and increased deployment. Improvement in cell power conversion efficiency is a key driving factor in reducing the cost of solar energy, which this proposal aims to achieve by developing industrially-compatible optical enhancement, surface passivation and emitter formation techniques for silicon solar cells. The methods developed as part of this project will be applied to the leading solar cell technologies based on mono- (c-Si) and multi-crystalline silicon (mc-Si). For c-Si, this is a rear junction (RJ) architecture also known as the interdigitated back contact cell, and for mc-Si, this is a front junction (FJ) architecture. To enhance the RJ cell technology, where the p-n junction is at the back of the cell and unaffected by the front surface texturing, the approach is to use a solution-based texturing technique that leads to optically black silicon surfaces. For the case of the FJ cell architecture, where formation of the p-n junction at the front surface alongside texturing has to be considered, gas-phase processes will be investigated. Upon developing effective antireflective surfaces for RJ and FJ solar cells the challenge becomes transferring the gain in photon capture to improvements in the efficiency of the cell. For this to take place the electrical properties of the surface must be studied, and methods developed to mitigate any electrical degradation due to the texturing processes. This project is uniquely positioned to address jointly the optical and electrical properties of the cells, and by doing so, aims to produce optimally textured surfaces that can be easily integrated into the manufacture of solar cells. The project teams at Southampton and Oxford will draw on their close collaborations with the world-leading research institutes at Fraunhofer ISE, Germany, and UNSW, Australia. This will enable the demonstration of the proposed texturing technology on state-of-the-art silicon solar cells, as well as providing access to advanced techniques in characterisation and processing. These collaborations will also promote knowledge transfer to the UK research community. A core principle of this proposal is to contribute to improving industrial solar cell production. For this, two strategic industrial collaborations have been established. Firstly Tetreon Technologies, the leading UK manufacturer of industrial tools for solar cell production, will be closely involved in the project, with the aim of subsequently developing industrial equipment and processes for export to the global market. Secondly Trina Solar, one of the world's largest cell manufacturers and the industrial leader in high efficiency cells, will provide insight into the market and industry needs that this project aims to address. They will demonstrate successful processes in an industrial environment from cell to module manufacture. Through these collaborations this project will leverage cutting edge expertise in the complementary areas of surface passivation and light trapping to tackle the challenge of developing photovoltaic technology. The project will deliver substantially improved efficiencies for silicon based solar cells and modules and, through close collaboration with UK and international companies, will allow the research undertaken to be rapidly exploited in the form of new tools and processes for export to the global solar industry. Alongside the expertise within the team, its academic and industrial networks form an ideal basis for the innovative and impactful research programme.

I have recently developed two new solar cells based on semiconductor nanotechnologies that offer the potential for higher efficiency and lower cost. In order to progress these technologies, specialist facilities are now required to gain a deeper scientific understanding of their advantages and to develop new implementations which will make renewable energy generation more competitive. In this Overseas Travel Grant, I will access the required specialist facilities and related expertise by taking my solar cells to laboratories in Singapore (Nanyang Technical University) and Germany (Fraunhofer Institute for Solar Energy) and performing three novel experiments. These experiments involve state-of-the-art equipment which are not readily available in the UK for example, at Nanyang Technical University, I will study the current pathways in my solar cells at the atomic scale as well as combining them with other solar cell technology to assess the potential for new low-cost, high efficiency solar cells that can be scaled up sustainably. Similarly, at the Fraunhofer Institute for Solar Energy, I will expose my solar cells to high optical concentration (more than 500 times the power of the sun at the Earth's surface) to maximise the contribution from nanometre sized quantum dots which capture more of the incident sunlight. Importantly, this research programme will also enable me to initiate new collaborations with world-leading experts. Through the exchange of knowledge and skills, it offers a unique professional development opportunity that I will exploit to benefit scientific research and innovation in the UK. This will be achieved by generating essential feasibility data for a deeper major programme of collaborative research that will involve industrial partners. The programme also contains several important opportunities for dissemination with the wider energy materials scientific community but also with young people and school teachers that are engaged with science, technology, engineering and mathematics subjects.

Keywords: membrane-based sensor; membrane permeability and damage; cross-validation/demonstration; technical development; staff exchange; project workshop This project can be divided into the following four categories of activity with the ultimate aim of transferring an interesting and unique technology to appropriate end users;SEAC, Unilever and ALcontrol Ltd and co-workers; IBMT, Fraunhofer:- (i) Cross-validation/demonstration. The University of Leeds has developed a unique and elegant biosensor which is sensitive to compounds and particles which damage and/or are permeable in biological membranes a property defined as biomembrane activity. The aim of this task therefore is to evaluate exactly how the Leeds biosensor assay compares with those currently employed by the end users in achieving the same or similar functions. This activity will provide a clear definition of the respective advantages and disadvantages of both the Leeds and the end users' techniques. This is necessary since although the Leeds biosensor is at prototype stage, it is essential that its performance is compared with other systems in their detection of the biomembrane activity of a common group of compounds. Particular attention will be paid to the similarity and differences in the parameters being measured by each technique. The outcome of this activity is, (a) to enable end users to determine whether it is advantageous to add this technology to their measuring systems and, (b) to enable Leeds to adapt their technology to specified applications. The impact is an increasing confidence in and acceptance by the user community of the capabilities of the Leeds device. 2. Technical development. The technical development will take the Leeds biosensor from the prototype stage to a routine sensing device which can be operated by skilled technicians. This improvement will include streamlining the data analysis and extending the device from one module to three or more modules which will will enable it be used in a high-throughput automated configuration. The outcome of this activity therefore is to transform the Leeds biosensor system from a lab prototype into one which can be used by skilled technicians in the end user laboratories in a form which is specified by them. The impact is an increasingly robust biosensing device where a perceived risk in its application has been decreased allowing a more ready take up by end users. 3. Exchanges and placements. This objective will allow (a) end user scientists to operate and become completely familiar with, the Leeds biosensor and (b) scientists from Leeds to fully evaluate the end-users' methods and requirements in order to assess exactly how the end user technology fits in with the Leeds biosensor technology. The outcome of this activity is to transfer the Leeds technology to end users as a complimentary system to their own. Currently the Leeds biosensor has not been adopted by an end user. This objective will enable the Leeds biosensor to have a direct user application which not only expands the user's facility but also validates and consolidates the Leeds biosensor's applicability. The impact is a transfer of the technology to the end user. 4. Facilitated dissemination. This objective will enable the Leeds scientists to communicate the project progress to the end users and for the end users to comment on the deliverables. An end of project workshop will be held where the project's final report will be presented. The open nature of the workshop with outside participants will ensure other potential end users can assess Nelson's technology with increasing confidence and judge whether it is suitable for their needs so expanding its remit. The outcome and impact of this activity is to facilitate further knowledge transfer of the Leeds technology and its take up by other commercial users in additional to SEAC and ALcontrol.

Perfusion imaging allows us to measure the vital role played by delivery of blood to the brain in keeping it supplied with nutrients and removal of waste. Any deviations of the blood supply from normal can be a sign of disease. In particular early and subtle changes in perfusion might mark regions of the brain which are affected by degenerative diseases such as dementia before other imaging signs become obvious. The technology exists and is increasingly widely available to image perfusion quickly and safely using Magnetic Resonance Imaging. Thus perfusion Magnetic Resonance Imaging could be a valuable tool in the understanding of dementias, as well as the diagnosis and monitoring of patients with dementia. The challenge that remains is making sufficiently specific measurements of subtle changes in blood supply that would be needed to make the technology truly useful for patients. This project addresses that problem in three ways: > Automated removal of errors associated with imperfect measurement, for example due to motion of the patient. > Methods to control for differences between patients due to their individual brain structure, allowing blood supply measurements to be compared between individuals or from a patient to a population of similar healthy adults. These methods remove uncertainties introduced by other differences between the brain's of individuals that are not related to perfusion. > Generation of personalised reference perfusion images for an individual patient against which their measured perfusion can be compared to detect changes specific to that individual. The methods and tools that are to be generated in this project will enable perfusion Magnetic Resonance Imaging to be used more effectively in the UK-wide effort to understand dementia and in the search for new and effective treatments. Ultimately the work done in this project will enable perfusion Magnetic Resonance Imaging to become a valuable clinical tool that can be used in the diagnosis and monitoring of individual patients with dementia.

Computer systems of all types tend to deteriorate in quality as they age and grow larger. As more and more changes are applied to a system by developers as part of system maintenance (either through the occurrence of a fault or change requests by the users) the net effect is usually to render the system more difficult to maintain and, with it, the risk of investing more faults in the same system. The decline of a system in this way has come to be known as 'code decay'. A technique that attempts to reverse that decay is refactoring. Refactoring refers to a process where a system is changed in such a way that the system does not change 'what' it does, it just changes the 'way' it does it. For example, one of the simplest refactorings that a developer can do is to rename a code artefact so that the purpose of that artefact is made clearer. Another refactoring may split an excessively large code artefact into two so that the system is more manageable as a result. The benefits of refactoring therefore include more understandable code, but, more significantly, in a far easier job in the future for developers. Many different developers may need to look at and change that code so it make sense to make that code as easily understood as possible. After any change (or set of changes) is made by a developer to a system, it has to be tested to ensure that the change has been applied correctly; as important is to ensure that the same change has not adversely affected other parts of the system. One down side of a decaying and growing system is that more and more tests need to be applied after a change has been made by a developer as the system fragments. This places a burden on the developer. Making a change to code is time-consuming enough; having to test the system as well doubles the effort required. The benefits of refactoring are, as we have said, more understandable and more manageable code. If that is achieved, then there naturally follows a reduction in the testing burden, since changes are made more effectively; moreover, there are less opportunities for 'side-effects' in other parts of the system causing faults; finally there is the added benefit of a general 'stability' to the system in size and manageability as it evolves over time. Although we know much about refactoring and testing as independent activities, there are many open research issues related to the link between the two areas. In fact, the problem has turned full-circle. The code that tests the system (tests are often computer programs as well) is becoming more difficult to maintain than the code it actually tests! Even more interestingly, we have been successfully applying refactorings in the recent past to information systems used in every day life. There is a vast amount of opportunity for applying refactoring principles to the test code itself, i.e., not only to the application code, but the code that tests that application.The purpose of the proposed research is to investigate the link between these two areas from three perspectives. Firstly, opportunities for, and benefits of, refactoring of the test code as just mentioned; secondly, the theoretical aspects of the link between refactoring and testing - since all sound practical work relies on an equally sound theoretical basis. For example, are some refactorings more 'complex' than others and, if so, by how much? Thirdly, can we collect 'empirical' data from real-world systems to determine the extent of the benefits of refactoring both applications and test code? These are the research questions that the REFTEST Network will address and summarises the research.