Researchers develop all-carbon solar substrate
updated 02:16 am EDT, Fri November 2, 2012
Durable material suitable for utility in extreme environments
Stanford University researchers in conjunction with a team from the University of Rochester have constructed the first solar cell created entirely out of carbon, giving an alternative to sometimes exotic and expensive materials used in normal photovoltaic cells. The material isn't intended for light panels, but rather the thin film material is possible to be applied out of solution, and could coat surfaces like paint.
For the study, the researchers replaced the materials found in conventional electrodes with one atom thick, walled nanotubes that are 10,000 times narrower than a human hair. The active layer used more nanotubes, along with buckyballs one nanometer in diameter.
"Every component in our solar cell, from top to bottom, is made of carbon materials," graduate student Michael Vosgueritchian said. "Other groups have reported making all-carbon solar cells, but they were referring to just the active layer in the middle, not the electrodes."
The cells aren't very efficient -- absorbing only near-infrared wavelengths of light, the all-carbon cell is less than one percent efficient. A commercial panel typically runs with between 10.5 and 25 percent efficiency. If applied to a 200 square foot surface, the coating would generate approximately 240W.
According to Vosgueritchian, "we believe that all-carbon solar cells could be used in extreme environments, such as at high temperatures or at high physical stress," he said. "But obviously we want the highest efficiency possible and are working on ways to improve our device."
