All-perovskite Multi-junction Solar Cells

A major global challenge of the present epoch is transforming our energy system to become clean, secure and efficient. A major challenge for the UK is ensuring industrial leadership in low-carbon energy technologies, which will dominate the future energy market, and "securing the economic benefits of the transition to a low-carbon economy". In this prosperity partnership, we have uniquely combined pioneering academic and industrial leaders in perovskite photovoltaics and will develop the underlying materials, science and technology, which will allow us to develop the next generation of multi-junction perovskite solar cells. The ambition of the project is to go well beyond the state-of-the-art, and therefore deliver over 37% efficient triple junction perovskite solar cells. This will be possible through a combined effort of new materials development, fundamental investigations, thin-film device engineering and interface modification, and significant effort on understanding and improving materials and device stability. The major technical outputs of the project will be to deliver technology at three different stages, for beyond project downstream development and manufacturing.

Metal halide perovskite solar cells are rapidly approaching performances that can rival those of crystalline silicon (c-Si). However, mainstream PV module manufacturing costs have continued to diminish so extensively over the last decade that now the cost of the module amounts to less than half the overall solar PV installation in utility scale projects. Most of the non-module costs, referred to as the balance of systems (BoS) cost, scale with area of deployed PV rather than power generated. Therefore, increasing the overall power output of the module per unit area, i.e. efficiency, is the surest means to continue to drive down the overall cost of installed PV generated electricity. Within this project we will develop the foundations for a viable, highly efficient, thin-film multi-junction perovskite PV technology with much higher efficiency than c-Si devices can achieve alone, ensuring a place for perovskite solar cells in a market estimated to be worth over $300bn by 2020. OXPV is pioneering the development and industrialisation of perovskite photovoltaic (PV) technologies. OXPV's "go-to-market" strategy is to boost the efficiency of existing Silicon PV, by coating perovskite cells on top of silicon wafers, and partner with existing silicon manufactures. However, the opportunity for an all perovskite thin-film technology is different. Over the next few years, the perovskite technology per-se will be de-risked, by real product entering the market in the form of perovskite-on-silicon tandem cells. Therefore, there exists an opportunity to establish independent manufacturing of the next generation all-perovskite multi-junction technology which we will develop in this project. This will be the seed which will enable a UK effort to capture a significant fraction of the future PV market. .
Beyond economic impact, there is overwhelming evidence that our increasing consumption of fossil fuels and the associated emission of carbon dioxide is leading to climate change. This has brought new urgency to the development of clean, renewable sources of energy, and to reduction of our energy consumption by developing new low energy consumption devices to satisfy the growing demand. Photovoltaic devices that harvest the energy provided by the sun have great potential to contribute to the solution. The fundamentally more efficient thin-film technology which we will develop here will enable the cost of PV electricity to continue to drop for decades to come, accelerating the transition to entirely clean electricity generation.

Historically, discussions and targets on mitigating climate change have been based on the ethos of how do we solve this challenge and how much is it going to cost us? Whereas, it is now very apparent that the PV technologies which are delivering clean energy, are set on a trajectory to not just match the electricity generation costs from fossil fuels, but to continuously and progressively undercut them. The next generation of PV technologies which we are developing here therefore offer the possibility of significantly reducing the global cost of power, and resultantly enabling a positive transformation in society and the standard of living across the globe.

Beyond commercial, economic, environmental and societal impact, the activities within this project will aid in the training and education of both scientists and the general public. The training of PDRAs and PhD students in this industrially relevant area will create an employment pool for jobs in research, R&D, energy sectors and other economic areas, and carry the knowledge and skills they acquire into those fields. Public outreach events, such as hands on experimental activities at schools, and lectures to the general public and professional societies, will be enhanced by the excitement of rapidly advancing research and technology in an area where there is already great public interest.