Climate change affects everyone on the planet through changing weather patterns particularly leading to increased occurrence of extreme weather which can, for instance, result in very intense rainfall leading to flooding or prolonged absence of rain leading to drought. Climate change is driven by increased atmospheric concentrations of greenhouse gases (e.g. carbon dioxide) which trap heat which would otherwise be dissipated away from the planet's surface. The biggest source of increasing carbon dioxide into the atmosphere is the burning of fossil fuels to generate energy (e.g. to generate electricity in coal or gas-fired power stations and/or in the internal combustion engines or cars/lorries/buses etc.).

Climate change is arguably the biggest and most urgent challenge currently facing humankind. The paradox is that global society is expanding rapidly and that society wants to use ever increasing amounts of energy whilst, at the same time, we must urgently and significantly reduce the amount of energy-related greenhouse gases we are releasing. At the same time, energy costs are on an upward trend which is predicted to continue for the foreseeable future.

The answer is renewable energy whereby energy is sustainably generated with no greenhouse gas emissions. However, current and predicted energy demand is huge and so the required scale of global renewable energy generation must match this. The most likely scenario is that future energy generation will rely on a patchwork of renewable energy sources (e.g. wind, hydroelectric, biomass, solar) with one energy source picking up the slack when another is generating poorly. However, this must still be produced at a cost that the customer can afford.

When considering solar energy, there is huge surplus falling on the Earth's surface every day (approximately 6,000 times more than annual global energy consumption). This suggests that for 10% efficient solar cells, covering 0.2% of the crust with solar panels would meet energy demand.

Hence, the primary challenge is to be able to manufacture solar cells at sufficient scale to meet this energy demand. Currently, about 90% of solar cell modules sold are crystalline silicon (cSi) which are sandwiched between two sheets of glass and then either bolted to frames on roof surfaces or floor mounted in solar farms. The problems with cSi modules are that they are manufactured using batch processes, which involves a lot of staff which makes it harder for the UK to compete because our labour costs tend to be higher.

For new solar cell technologies to compete with cSi, they must be available at the right cost to the customer. They must also contain low embodied energy (that is the energy which is takes to manufacture them). Combining these two factors will reduce the initial cost the customer which will increase uptake. It will also significantly reduce pay-back times; i.e. the time the solar cells must be installed before the customer has saved enough money on their energy bills to have paid off the initial purchase costs.

Perovskite solar cells (the subject of this research) were discovered by Professor Snaith at Oxford University in 2012. These devices offer great potential for very large scale solar cell uptake because they convert solar energy to electricity very efficiently and all the device components are abundant. The device components are also printable onto flexible substrates, which means that this technology should be suitable for roll-to-roll processing which is not labour intensive and which can be very rapid. Printing devices onto flexible substrates means that it should also be possible to integrate these devices into commercial products; for instance for mobile device charging such as mobile phones or onto the outside of buildings to generate energy at the point of use.

Potential Impact:
1. The proposal will scale perovskite PV devices from lab-scale devices (1cm2) to modules using pilot scale continuous, roll-to-roll manufacturing which opens the potential for very large scale production.

2. The research will develop the fundamental understanding to scale perovskite device raw materials which will enable the creation of a supply chain.

3. The research will develop new understanding of processing multiple layer, nanoscale materials on low cost substrates which are not perfectly flat. This new knowledge will be transferrable to a wide range of new, advanced materials which often use nanoscale substances.

4. The research will produce understanding of failure mechanisms and mitigation strategies to extend perovskite module lifetimes under indoor and outdoor exposure conditions.

5. The research will generate high impact journal publications (e.g. Nature and Energy & Environmental Science) and be presented at international conferences (e.g. MRS, APS, ACS, EU-PVSEC).

6. The project will generate highly trained and inter-disciplinary scientists and engineers to support the growing PV and advanced materials industry.

7. By developing a new PV manufacturing technology in the UK, the research will generate significant wealth and create jobs in the UK; e.g. it has been estimated (European PV Industry Association) that PV manufacturing creates 3-7 direct jobs in production and between 12 and 20 indirect jobs per MWp.

8. The proposal will help deliver UK Govt. targets to reduce greenhouse gas emissions to < 80% of the 1990 value by 2050 including work on building integrated PV (BIPV) to help deliver DECC policy of "buildings as powers stations".

9. The proposed research will improve global health and quality of life by reducing greenhouse gas emissions by replacing fossil fuels with renewable energy generation which will reduce the impact of climate change.

10. To disseminate the impact of the project to wider society, the Swansea-led Materials Live project will coordinate impact activities from schools
engagement to the production of lab demonstrator systems for public showcase.

11. The proposal will generate intellectual property (IP) and the Project Management Team will manage the exploitation of this IP through project partners, SPECIFIC IKC partners and/or new spin-out companies.