Photovoltaics (PVs) cells will play a major role in the worldwide transition to more sustainable sources of energy. There has been a vast scale up in the deployment of PV cells driven by the drastic price reduction of Si photovoltaics (Si-PVs). It is now widely accepted that increases in PV efficiency are key to pushing PV deployment further and continuing to lower costs. However, after decades of research and development Si-PVs are approaching the theoretical limit for power conversion efficiencies (currently 26.7% out of a possible 29.4%) as determined by the Shockley-Queisser limit, due to thermalisation losses. There is currently no commercially deployed technology and can overcome this challenge.
This project, Photon-Multiplication to Boost Si Photovoltaic Power Conversion Efficiency (PM2PV), sought make a proof of concept demonstration of a new technology – a photon multiplication film (PMF), which overcomes these fundamental thermalisation losses by converting high energy photons into double the number of low energy photons using a process called singlet fission. A PMF film could raise the efficiency of the best Si-PVs from 26.7% to 32.5% (a 20% increase in efficiency). This all optical approach has several advantages over other technologies currently being researched such as tandem cells. For instance, since the output of the PMF is photons, they can be directed towards the PV cell without any change in cell design, making it a ‘drop in’ solution, compatible with 95% of current PV manufacturing capacity as well as future designs and hence requiring little or no change to current manufacturing lines and hence very low capital expense.
PM2PV has resulted in the development of a new class of luminescent photon multiplication materials. The filing of patents around this work is currently be explored. Key industrial links with have been established with companies across the EU, the business case has been developed and validated and the economics of a potential product have been established. The materials are currently being translated to industry. Key steps such as efficiency and stability validation via industrial partners under real world conditions remain and industry standard tests musts be passed in the years to come. But it it hoped that a first product could enter the market in 2028.
If successful the technology developed in PM2PV could increase the efficiency of PV modules by 10% (relative), adding more than 1TW to world electricity production by 2050, helping to accelerate the energy transition and meet the worlds climate change targets.
