In today’s MIT Technology Review they talk about how researchers at Notre Dame have “demonstrated a way to significantly improve the efficiency of solar cells made using low-cost, readily available materials, including a chemical commonly used in paints.”
What they’ve done is to add single-walled carbon nanotubes to a film made of titanium-dioxide nanoparticles, which doubles the efficiency of converting UV light to electrons. Titanium oxide is the main ingredient in while paint.
While there’s been alot of press about using nanoparticles in solar cells (instead of silocon), so far all cells made from this process have suffered from very low efficiencies, compared to conventional solar cells. The carbon nanotubes increase efficiency by channeling the electons directly to the electrode.
These new cells are not yet considered practical, however. Right now the cells only work on ultraviolet light, while much of the visible spectrum is reflected back. But the researchers have already begun to work on changing the nanoparticles using a technique of applying a one molecule think layer of light absorbing dye.