Researchers from the US Department of Energy’s Lawrence Berkeley National Laboratory and the University of California, Berkeley have devised a way to make low-cost, highly efficient solar cells from virtually any semiconductor material. This would let manufacturers use inexpensive materials previously deemed unsuitable for solar cell manufacturing, such as metal oxides, sulfides, and phosphides. The researchers say their technique could stimulate solar energy use. “It’s time we put bad materials to good use,” stated Alex Zettl, physics professor at UC Berkeley and director of the Center of Integrated Nanomechanical Systems -- who is leading the research. “Our technology allows us to sidestep the difficulty in chemically tailoring many earth abundant, nontoxic semiconductors and instead tailor these materials simply by applying an electric field.” Typically, solar cells are made from expensive photovoltaic materials such as cadmium telluride or copper indium gallium selenide thin films. The researchers’ screening-engineered field-effect photovoltaics method uses an electric field effect, rather than chemical dopants, to alter a semiconductor’s conductive capabilities. The technique also creates devices that perform self-gating functions, which means they do not need external power for gating. These gates can also function as an antireflection coating. The researchers published their work in Nano Letters. (Science Daily)(Lawrence Berkeley National Laboratory)(Nano Letters)
