Dye-sensitized solar cells, also known as Grtzel cells for one of the their co-inventors Michael Grtzel of the 'cole Polytechnique Fdrale de Lausanne, have been a promising alternative to silicon cells since 1991.
Basically, they use an organic dye that captures the incoming photons from sunlight to produce excited electrons.
The design of these cells typically includes a transparent, conductive coating that serves as the anode. The coatings are usually made from an oxide such as titanium dioxide and are placed on glass. Using glass has its obvious limitations and alternatives such as platinum are prohibitively expensive.
As a result, researchers have been experimenting with carbon nanotubes to replace these films. It was necessary that the CNTs achieve optimal transparency, conductivity and catalytic function. Unfortunately, instead of being optimal, they were more in the mid range for these areas.
But researchers have found that if they the give the CNTs imperfections by exposing them to ozone, their catalytic function improves dramatically.
More efficient and cheaper are the demands of renewable energy alternatives. Nanotechnology research seems to be listening.