Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have produced solar cells using nanotechnology techniques at an efficiency – 18.2% – that is competitive. The breakthrough should be a major step toward helping lower the cost of solar energy. NREL tailored a nanostructured surface while ensuring that the light-generated electricity can still be collected efficiently from the solar cell. The researchers made nano-islands of silver on a silicon wafer and ...