IBM Improves Efficiency of Solar Cell with Low-Cost Materials

IBM researchers have increased by 40 percent the efficiency of a thin solar cell that can be applied like ink and that uses widely available materials. The new cells can convert solar energy into electricity with an efficiency of 9.6 percent, a significant improvement on the 6.7 percent high for existing technologies and close to the level that would make the cells practical for use in commercial solar panels, according to a report published in the journal Advanced Materials. The new technology uses a semiconductor material made of fairly abundant elements — including copper, zinc, tin, sulfur and selenium — and utilizes an inexpensive ink-based process in creating the cell. Experts say some existing solar technologies have limited long-term potential because of the cost or relative rareness of materials used. For instance, the leading “thin film” solar cell technology currently in existence uses a material that includes tellurium, a rare element that limits the ability to mass produce the solar cells. Matthew Bear, a senior scientist at the National Renewable Energy Laboratory, called the IBM advance a “breakthrough for this technology.” Researchers hope to reach an efficiency of 12 percent in the laboratory in order to convince manufacturers of the technology’s commercial viability.