A new wire twist on silicon solar cells

US researchers have devised a way to make flexible solar cells with silicon wires that use just 1% of the material needed to make conventional solar cells. The eventual hope is to make thin, light solar cells that could be incorporated into clothing, for instance but the immediate benefit is cheaper and easier-to-install solar panels, the researchers said. The new material, reported uses conventional silicon configured into micron-sized wires (a micron is one-millionth of a meter) instead of brittle wafers and encases them in a flexible polymer that can be rolled or bent. "The idea is it would be lower cost and easier to work with by being more flexible than conventional silicon solar cells," Michael Kelzenberg of the California Institute of Technology in Pasadena, who worked on the study. The study is among the latest to combine the flexibility of the new organic or carbon-containing films with the high efficiency of silicon, which is heavy and stiff. Kelzenberg said the material uses about 1/100th as much silicon per cell area as a silicon wafer. "It is potentially a route to bypass many of the costs associated with producing solar cells," he said. More testing is needed but Kelzenberg said the material would be about 15% to 20% efficient, about the same level as solar cells used on roofs to heat homes.