from the the-diamond-age dept.
An article on Space Daily.com reports researchers at Vanderbilt University have created a prototype diamond-based thermionic solar cell that is potentially 3 to 4 times more efficient than conventional silicon-based cells. The operation of the diamond cells depends on their nanoscale properties.
The cells use diamond films covered with millions of microscopic pyramids: about 10 million per square centimeter. When heated, the tips of these pyramids, which are only a few atoms across, emit streams of high-energy electrons. At the nanoscale, the laws of physics favor the efficient production of high-energy electrons. "It is this nanoscale physics that makes the device work," says Vanderbilt Prof. Timothy S. Fisher, who led the research. He collaborated with Weng Poo Kang, an associate professor of electrical engineering and computer science. The bottom of the diamond film is laminated to a metal sheet that acts as a cathode. When heated, the tips of the tiny pyramids emit streams of electrons that flow across the intervening vacuum to the anode, creating an electric current.