Flexible perovskite solar cells with all-carbon electrodes - a pathway to low-cost and stability

The research within the programme grant addresses the next generation of printed PV technologies which could deliver solar energy with far greater functional and processing flexibility than c-Si or traditional compound semiconductors, enabling tuneable design to meet the requirements of market applications inaccessible to current PV technologies. In particular, we seek to advance photovoltaics based upon organic and perovskite semiconductors - materials which can be processed from solution into the simplest possible solar cell structures, hence reducing cost and embodied energy from the manufacturing. These new technologies are still in the early stages of development with many fundamental scientific and engineering challenges still to be addressed. These challenges will be the foci of our research agenda, as will the development of solar cells for specific applications for which there is currently no optimal technological solution, but which need attributes such as light weight, flexible form factor, tuned spectral response or semi-transparency. These are unique selling points of organic and perovskite solar PV but fall outside the performance (and often cost) windows of the traditional technologies. Our specific target sectors are power for high value communications (for example battery integratable solar cells for unmanned aerial vehicles), and improved energy and resource efficiency power for the built environment (including solar windows and local for 'internet of things' devices). In essence we seek to extend the reach and application of PV beyond the provision of stationary energy. To deliver our ambitious research and technology development agenda we have assembled three world-renowned groups in next generation PV researchers at Swansea University, Imperial College London and Oxford University. The assembled team spans the fundamental and applied science and engineering needed to answer both the outstanding fundamental questions and reduce the next generation PV technology to practise. Our research programme also involves industrial partners from across the PV supply chain - early manufacturers of the PV technology, component suppliers and large end users who understand the technical and cost requirements to deliver a viable product. The programme is primarily motivated by the clear need to reduce CO2 emissions across our economies and societies and our target sectors are of high priority and potential in this regard.

The specific focus of the DPhil student hosted in Oxford is related to advancing the understanding of degradation, stability and processability of solution processed metal halide perovskite films and PV devices. A key target is to employ printable carbon electrodes on stable "p-i-n" perovskite solar cells and develop and understand the role of multi-layer material stacks to enable high performance alongside high stability.