Efficient Plastic Solar Cells Closer to Becoming Reality

The quest to make solar panels cheaper and more efficient continues to move forward, thanks to progressive research into plastic solar cells which could pave the way to cheaper solar energy.

An imaging technique which makes it possible to observe light-emitting excitons as they diffuse in a new material, has been developed by two physicists in America. Created by light, excitons play a pivotal role when it comes to harvesting solar energy using plastic solar cells.

The new material, known as rubrene, has been discovered to have remarkable electronic properties, and is one of a new generation of single-crystal organic semi-conductors.

Ivan Biaggio, professor of physics at Lehigh University in Bethlehem, Pennsylvania, and Pavel Irkhin, a PhD candidate, have conducted research using an advanced imaging technique that has never been seen before, which observes the long-range diffusion of excitons – an electron that absorbs the energy in light – in an organic crystal.

It’s understanding this diffusion process which is an obstacle limiting the efficiency of plastic solar cells. In most commonly used silicon systems, the intake of light directly induces a current, but in exciton diffusion, light creates excitons instead.

In plastic solar cells, excitons diffuse toward specially designed interfaces. By driving electrons into an external circuit, it creates the flow of electrons, which we know as an electric current.

In other news, research conducted by British scientists into solar technology suggests that plastic solar cells could be printed to create a cling-film type substance, which can be ‘spread’ to make ‘ultra-cheap solar panels for domestic and industrial use’. The scientists from Cambridge and Sheffield universities believe that efficient and cheap polymer solar cells – which can cover extensive areas – have the potential to help us move towards a new age of renewable energy.