Optic Fibre Solar Cells: Dye-based Nanotech 3D Energy Harvesting

Posted on 05. Nov, 2009 by Ross in New Technologies

Could conventional photovoltaic solar cells finally have met their match?

Researchers at the Georgia Institute of Technology have developed a new three-dimensional solar cell structure using optic fibres and dye-sensitised nanowires to produce a solar cell which with further optimisation could supercede the efficiencies of silicon-based photovoltaic solar cells.

Dye-sensitised solar cells have been around for a while now, using a photochemical reaction to generate electrical energy from the sun. Light hitting dye molecules results in the promotion of electrons into neighbouring nanostructures, which creates a voltage drop across the cell. They can be made for a tiny fraction of the cost of silicon photovoltaic solar cells (as well as their manufacture being far less polluting than semiconducting silicon), and are flexible and robust. However, dye-sensitised solar cells suffer from much lower energy conversion efficiency than silicon solar cells.

Optic Fibre Dye-sensitised Solar Cells

The Georgia team realised that increasing the surface area across which the conversion could take place was the key to increasing efficiency, and have published their novel approach to the problem in the latest edition of Angewandte Chemie International.

Sunlight is harvested by the open ends of optic fibres at a surface. The light then travels down the fibres, which have had their outer coatings replaced by bundles of zinc oxide nanowires coated in dye molecules. The fibre-dye-nanowire interface then provides a far greater surface area for conversion to occur on than in a simple two-dimensional dye-sensitised solar cell.

Because the light only needs to enter the end of the optic fibre, the light can be conducted away from the surface and converted by the dye molecules further inside a building, giving a limitless range of solar cell design possibilities.

Image of optic fibre by Jared Zammit @ Flickr under a Creative Commons BY-SA license.