New component makes solar cells more efficient

The world's energy needs are growing constantly, all while more and more environmental issues are observed as a consequence of increasing carbon dioxide emissions. This increases pressure to use renewable energy sources, such as solar energy, but the production of solar cells is still too costly to compete with available energy sources.

In her thesis, Sandra Feldt has researched dye-sensitised solar cells. These can be made from cheap, environmentally friendly materials and have a great potential for reducing the price of solar cells compared to available solar cell technologies on the market. The solar cells can be made in different colours or transparent, which makes them interesting for many different applications such as integration in buildings.

Dye-sensitised solar cells convert sunlight into electric energy through a dye adsorbed to a titanium oxide semiconductor. The system can be likened to photosynthesis where chlorophyll in green leaves absorbs sunlight for converting water and carbon dioxide into oxygen and carbohydrates. And similarly to a battery, a solar cell has an electrolyte between the positive and negative poles which transports charges.

The thesis studies a new component in the electrolyte, cobalt complexes.

“We showed for the first time that a a higher voltage and efficiency could be achieved by using cobalt complexes in combination with organic dyes in the dye-sensitised solar cell”, says Sandra Feldt.

This new electrolyte component helps achieve a record-level efficiency of 12.3 per cent. The research group’s discovery has affected research on dye-sensitised solar cells across the world.

You can read more about the thesis and download it here.

The thesis will be defended on the 22 March.