Perovskite solar cells are one of the newest and most exciting materials in the world of solar cell research. In little over 10 years their lab scale efficiencies have advanced from 8% to over 25%, putting them on a par with market leading silicon solar cells. However, after a decade's worth of interest and investment, this potentially revolutionary solar cell has not made it on to the market yet. There are several important barriers to commercialisation for perovskites, principally: 1. Issues with stability of perovskite materials, 2. Concerns around the use of toxic element such as lead, and, 3. Issues in transitioning to scalable manufacturing processes. In order to overcome these barriers, we propose a more holistic approach to design and fabrication of perovskite solar cells, which considers both toxicity and scalability, as well electrical efficiency during the optimisation process. The aim of this project to develop safe, stable and printable perovskite solar inks. This will be achieved by developing tin-based perovskite solar cells and exploring the use of ionic liquids in the solvent system to create a stable non-toxic ink that can be used in an inkjet printer. Ionic liquids are an impressive new solvent option for perovskite processing, exhibiting many favourable properties, such as solubility, low toxicity and stability. Most promising of all is the tunability of their viscosity, a key parameter in ink formulation for printing and thin film processing, which is yet to be explored. The goal is to fully print a tin-based perovskite solar cell in atmospheric conditions. This will be a revolutionary solar cell product that contains no harmful materials, is more easily recyclable and can be fabricated at lower costs.

This programme assesses the feasibility of applying photovoltaic paint directly to product surfaces during the manufacturing process. The result will be seamlessly integrated photovoltaic elements which generate clean electricity (zero carbon emissions) at the point-of-use of the product. Not only will this enable more sustainable applications but it will also enable applications where automatic battery charging, reliability and mobility are critically important. The research is transformative because it will define a new manufacturing sub-field: product integrated photovoltaics (PIPV) which crosses sectors and length scales and therefore has strong disruptive potential.

The world is currently undergoing one of the biggest transformations in energy usage since the industrial revolution. From the poorest to the richest nations, our planet has shown the consequences of climate change, and the exhaustion of some fossil fuels is now in the foreseeable future. We have started to change the way we generate, distribute and use energy throughout the world. Solar power is one of the most environmentally favourable sources, which in principle could provide all the energy required for the planet. Solar cells use the photovoltaic effect to convert solar energy to usable electrical energy, and thus are a key technology to provide the world with renewable, inexpensive and reliable electricity. Photovoltaics research and industry have experienced enormous advancements in the last two decades. The most important material by far in the photovoltaics field is silicon. Silicon today accounts for over 85 % of the photovoltaics market, and has over 140 GW of installed capacity. Current silicon solar cell systems have an energy payback time of only 2-4 years with 30-years lifetime. Their cost of power generation is now falling below 0.5 $/W, and in some areas of the world they are already cost effective for supplying grid electricity. Silicon photovoltaics is therefore an extremely promising technology where significant technological improvements are still possible which will ensure further price reductions and increased deployment. Silicon solar cells capture solar energy when light is absorbed near the cell's surface and it creates electrical charge carriers. These carriers then diffuse through the cell, get collected at one of the contacts and are then able to deliver electricity. In this process many carriers are lost due to the imperfections of the material. The conversion efficiency of a solar cell is therefore limited by this loss of charge carriers at imperfections and defects. The surface of the cell represents a major material defect. The reduction of charge loss at the surface, termed passivation, is hence a critical feature requiring improvement. This project aims to improve the efficiency of silicon solar cells by optimising passivation using the cost-effective technologies proposed and patented as part of my previous research work. It is rare that a newly proposed technique could produce a step-change in the efficiency of passivation in commercial solar cells. This grant application will specifically enable that step-change to be developed. My research programme includes the fabrication, processing and characterisation of different passivation coatings used in solar cell manufacture. Different methods of producing the coatings and enhancing their passivation properties will be studied. Techniques to deposit the coating will include chemical and physical vapour deposition. In each case the key importance will be the characteristics of the layer with respect to storing excess electric charge that will be especially introduced. The research will be carried out at the Oxford Materials department, in close partnership with four UK manufacturing companies and a leading overseas research centre, the Fraunhofer Institute for Solar Energy Systems ISE. This institute will provide processing and characterisation facilities, staff time and state-of-the-art custom-made solar cells, and will also help interface the outcomes of this collaboration to the solar cell industry worldwide. Overall, this project will combine a strong team of academics and industry to improve efficiency and reduce the cost of semiconductor solar cells, thus paving the way for wide deployment and uptake of a technology with the potential to provide the world with abundant renewable and reliable energy.

A wealth of world-leading international research is aimed at addressing the global challenges of energy (both generation and storage), climate-change and the problems associated with finding sustainable methods to meet our increasing energy demands. Much of this effort focuses on making existing technology more robust, efficient and cheaper or discovering new methods to convert, store and transmit renewable energy. For engineers, chemists, biologists and physicists working within the confines of their own research fields, it is impossible to recognise all of the key problems for given energy system. These problems present on an extremely broad range of length scales (nm-m) and consequently calls for significantly more collaboration between the physical science and engineering to transmit the success of new materials discovery and understanding of the behaviour of these new materials to achieve durable, efficient, sustainable and manufacturable energy systems. The North East Centre for Energy Materials (NECEM), formed between the universities of Newcastle, Durham and Northumbria, seeks to unite the broad range of expertise present at the three sites to tackle a grand challenge of energy materials and will make it possible to cooperate widely with local, national and international industry. The main focus of NECEM will be to address one of the most fundamentally critical elements of all energy systems, namely the interfaces between the materials within it and their interaction with the environment in which they operate. NECEM aims to be a world-leading programme on the understanding and manipulation of such interfaces in energy materials. The vision is to identify, exploring our unique blend of materials discovery, analysis techniques and energy applications new approaches operating over the full range of length scales (nm-m) that overcome existing limitations, such as corrosion, charge trapping, marine fouling. By addressing previously unexplored directions NECEM has the ability to provide an urgently needed step change in the science and engineering of materials that use, generate and store energy more efficiently. The assets of NECEM include the breadth of expertise within marine energy (tidal and wave energy), solar (photovoltaic and solar fuels by photo-electrochemistry), fuel cells (hydrogen and alcohol based, also enzymatic and microbial), energy storage (Li-Ion, redox-flow batteries), biomass (gasification, fermentation and direct conversion to heat or even electricity) and local smart grid structure (with concurrent production and consumption of renewable energy). We invite the Energy Materials community to engage with our centre to access this expertise and our unique blend of surface processing and characterization techniques distributed across the three sites. Probing and manipulating processes occurring at surfaces and interfaces is exceptionally complex but by combining our state-of-the-art facilities, which are ideal for this challenge, and our expertise in modelling behaviour in materials to compete systems, we can drive the development of new durable, efficient and sustainable energy solutions. We are geared towards cooperation with other centres in the UK in order to be able to cover a broad portfolio of all relevant energy material problems. This centre has the strong advantage of close proximity and brings together expertise from neighboring universities in the North East of England. Importantly this will enhance knowledge exchange and collaboration increasing the probability of success of the centre. It is also very attractive for additional funding both within the UK and in Europe.

The EPSRC Centre for Doctoral Training in Renewable Energy Northeast Universities (ReNU) is driven by industry and market needs, which indicate unprecedented growth in renewable and distributed energy to 2050. This growth is underpinned by global demand for electricity which will outstrip growth in demand for other sources by more than two to one (The drivers of global energy demand growth to 2050, 2016, McKinsey). A significant part of this demand will arise from vast numbers of distributed, but interconnected devices (estimated to reach 40 billion by 2024) serving sectors such as healthcare (for ageing populations) and personal transport (for reduced carbon dioxide emission). The distinctive remit of ReNU therefore is to focus on materials innovations for small-to-medium scale energy conversion and storage technologies that are sustainable and highly scalable. ReNU will be delivered by Northumbria, Newcastle and Durham Universities, whose world-leading expertise and excellent links with industry in this area have been recognised by the recent award of the North East Centre for Energy Materials (NECEM, award number: EP/R021503/1). This research-focused programme will be highly complementary to ReNU which is a training-focused programme. A key strength of the ReNU consortium is the breadth of expertise across the energy sector, including: thin film and new materials; direct solar energy conversion; turbines for wind, wave and tidal energy; piezoelectric and thermoelectric devices; water splitting; CO2 valorisation; batteries and fuel cells. Working closely with a balanced portfolio of 36 partners that includes multinational companies, small and medium size enterprises and local Government organisations, the ReNU team has designed a compelling doctoral training programme which aims to engender entrepreneurial skills which will drive UK regional and national productivity in the area of Clean Growth, one of four Grand Challenges identified in the UK Government's recent Industrial Strategy. The same group of partners will also provide significant input to the ReNU in the form of industrial supervision, training for doctoral candidates and supervisors, and access to facilities and equipment. Success in renewable energy and sustainable distributed energy fundamentally requires a whole systems approach as well as understanding of political, social and technical contexts. ReNU's doctoral training is thus naturally suited to a cohort approach in which cross-fertilisation of knowledge and ideas is necessary and embedded. The training programme also aims to address broader challenges facing wider society including unconscious bias training and outreach to address diversity issues in science, technology, engineering and mathematics subjects and industries. Furthermore, external professional accreditation will be sought for ReNU from the Institute of Physics, Royal Society of Chemistry and Institute of Engineering Technology, thus providing a starting point from which doctoral graduates will work towards "Chartered" status. The combination of an industry-driven doctoral training programme to meet identifiable market needs, strong industrial commitment through the provision of training, facilities and supervision, an established platform of research excellence in energy materials between the institutions and unique training opportunities that include internationalisation and professional accreditation, creates a transformative programme to drive forward UK innovation in renewable and sustainable distributed energy.