The Solar Power of Chemistry

Dr Neil Robertson is a Reader in Inorganic and Materials Chemistry at the School of Chemistry. Neil is a member of the SUPERGEN Excitonic Solar Cells Consortium which is a group of research scientists from eight UK universities working together to do scientific research on Excitonic Solar Cells.

The developing energy crisis can be a depressing topic with global warming and ever-rising energy prices. Amongst the doom and gloom however, there is new hope in the steady rise of solar power as an alternative to fossil fuels. A single hour of solar radiation is enough to provide human energy demands for an entire year. In this context, photovoltaic cells, mostly made from silicon, are benefiting from ever lower costs through economies of scale in manufacturing. Some of these cells have even found their way onto my roof!

To ensure however, that solar energy can be exploited as much as possible we need new types of cells that may be portable, light-weight, robust, flexible or even semi-transparent. So-called Excitonic solar cells, made from polymers, oxides, dyes and other molecules are attracting much interest as they offer the chance to fulfil these extra demands.

Excitonic solar cells could provide power for our portable gadgets because they are light-weight, non-toxic, easy to make, can be made robust and bendy and use cheap and readily available materials. They could charge our mobile phones and other gadgets, be easily packed away and carried around with us and could thus revolutionise the way we use electricity. They could also be used in indoor applications and are better at absorbing lower levels of sunlight (including the diffuse light we get through clouds) than traditional solar cells.

Neil in the lab

In my research group, we synthesise and study new materials for excitonic solar cells, including new dyes for light harvesting, new molecular materials for electron or hole transport, and molecules to modify the surface of metal oxide nanoparticles. Although we make and test our own solar cells, we also collaborate with physicists and engineers to take advantage of their additional expertise in optimising cells and applying detailed optoelectronic analysis. Accordingly, we work within both UK (Supergen) and international (UK-India) research consortia and this multidisciplinary approach makes the field very exciting and educational for research students.

The application of excitonic solar cells is not limited to portable power in developed countries. With 1.6 billion people on our planet having no access to electricity (and even more limited to an irregular supply), rural communities in the developing world could also have their lives transformed. Established silicon solar cells have already led the way, and the advent of robust, light-weight, cheap excitonic cells offer a whole new opportunity to accelerate the uptake of solar power.

Solar cells on Neil's roof

Neil practices what he preaches by installing his solar cells on his own roof.

For more information on excitonic solar cells and the SuperGen Consortium as well as lots more information about solar energy, visit the Solar Spark website.