By Renewable Energy Focus staff

As the thickness of the gold use is 8 nm, the electrodes still have the potential to be relatively cheap. It can also be recouped from organic solar cells at the end of their lives.

Organic solar cells have long relied on Indium Tin Oxide (ITO) coated glass as the transparent electrode, a complex, unstable material with a high surface roughness and tendency to crack upon bending if supported on a plastic substrate. Indium is also in short supply making it relatively expensive to use.

An ultra-thin film of air-stable metal like gold would offer a viable alternative to ITO for organic solar cells, but until now it has not proved possible to deposit a film thin enough to be transparent without being too fragile and electrically resistive to be useful.

Research led by Dr Ross Hatton and Professor Tim Jones in the University of Warwick ’s Department of Chemistry has developed a rapid method for the preparation of robust, ultra-thin gold films on glass. The method can be scaled up for large area applications like solar cells and the resulting electrodes are chemically very well-defined.

Dr Hatton says: “This new method of creating gold based transparent electrodes is potentially widely applicable for a variety of large area applications, particularly where stable, chemically well-defined, ultra-smooth platform electrodes are required, such as in organic optoelectronics and the emerging fields of nano-electronics and nano-photonics”