Solar cells which are made using a new ruthenium-based dye have achieved record levels of efficiency in stringent test conditions, it has been reported this week.

Although dye-sensitised solar cells have long been regarded as having huge potential, conventional solar cells tend to use silicon to attain the required standard of 15 per cent efficiency in full sunlight.

However, researchers in Switzerland and China have now bucked the trend by using non-volatile electrolytes in the dye-sensitised variety, leading to an efficiency of ten per cent.

As Tonio Buonassisi, Professor of Mechanical Engineering at MIT, explained to Technology Review: "[This] pushes the technology close to over the 'ten percent hump', which is where a thin-film technology needs to be to be economically competitive."

The advance is particularly significant because the dye-sensitive cells can use a range of materials such as glass, plastic, ceramic or metal, thus increasing the possibility of manufacturing them simply and inexpensively.

And although efficiency levels of 11 per cent have been achieved before, the cells used in those tests were considered to be too volatile and impractical to be pursued further.

It is unclear at this stage whether the ruthenium-based dyes will be commercially viable as the metal is fairly rare, but the new advances appear to suggest that the durability of dye-sensitised cells have been improved.

The research was conducted by dye-sensitised cells inventor Michael Gratzel, a Chemistry Professor at the École Polytechnique Fédérale de Lausanne, and Peng Wang, a Professor at the Changchun Institute of Applied Chemistry, part of the Chinese Academy of Sciences.



Source:

Better Plastic Solar Cells (07/11/08)
http://www.technologyreview.com/energy/21649/?nlid=1493&a=f

New solar cells reach record efficiency (31/10/08)
http://www.plentymag.com/blogs/edge/2008/10/new_solar_cells_reach_record_e.php