Roll-to-roll printing processes for the manufacture of organic photovoltaic (OPV) devices on flexible substrates
The printing and coating of functional inks to manufacture ‘organic photovoltaics’ (OPV) has the potential to reduce the cost of solar electricity generation, opening up many new market opportunities for the technology. IDTechEx estimates that the OPV market today worth is $4.6 million and forecasts that it will rise to $630 million in 2022.
When scaled, fabrication of OPV modules over large area plastic substrates can reduce production costs considerably. However, a key benefit of OPV technologies is their potential for integration with other materials and products, opening up new applications for electricity generation and energy harvesting from a renewable resource. For example OPV films can be laminated, or coated, onto substrates and components as part of steps in production and manufacturing.
Funding enabled the research team, led by Professor Neil Greenham, to focus on taking previously discovered materials to develop a process for manufacturing OPV devices using large-area R2R production techniques within the Printed Polymer Photovoltaics (3PV) project.
The project investigated the process steps required to pattern plastic substrates, deposit active semiconductor layers over large areas and interconnect the cells. In establishing the steps and translating cell fabrication to large-area R2R production techniques, while maintaining higher efficiencies achieved in lab results, Greenham’s team generated fundamental process IP that is applicable to a range of materials sets.
3PV resulted in the development of processes for device fabrication that could be scaled for full production, taking into account the anticipated advances in OPV efficiencies and other performance criteria, thereby taking research closer to market.
The funding from CIKC was instrumental in the University of Cambridge’s negotiations with stakeholder Carbon Trust to launch the Advanced Photovoltaic Research Accelerator. The Accelerator resulted in the spin-out of Eight19 in September 2010, with £4.5 million in funding from Carbon Trust and European specialty chemicals company Rhodia.
Based in premises on the Cambridge Science Park, Eight19 employs the four University of Cambridge researchers originally working on 3PV, a CEO and additional staff. In January 2012 the company installed a printing facility that includes a multi-station R2R machine able to deposit and pattern liquid active layers for solar modules at a peak linear speed of over 3.6 km an hour.
In addition to developing a production process for printed polymer solar cell technology, early on Eight19 identified a commercial application and product, a portable pay-as-you-go (PAYG) solar-powered lamp and phone charger for off-grid markets where millions are without access to electricity, opening up potential markets for the company’s OPV modules in future. The product, called Indigo, is made from commercially available silicon modules and LEDs.
The subsequent, rapid success of Indigo and the PAYG business model led to Eight19’s decision in 2012 to set up its own spin-out, Azuri Technologies Limited. This will allow Eight19 to concentrate on developing its printed plastic solar technology and Azuri to focus on expanding its markets and product family and each to access new sources of finance and commercial partnerships to support their respective operations.
‘CIKC funding has allowed us to take our OPV research programme a step closer to manufacturing than our normal funding sources would have allowed. Transferring the technology to a company that is focused on taking it to market is exactly what we wanted to achieve,’ says Greenham.
Eight19 continues to be actively engaged with the Optoelectronics Group of the Cavendish Laboratory. Eight19 is also a partner on a collaborative project supported by the European Union’s Seventh Framework Programme (FP7). Running for three years, Clean4Yield aims to overcome critical challenges to improve yields in large-scale R2R production of OPVs and OLEDs.