A coating similar to that used on eyeglasses could reduce glare and boost efficiency for photovoltaics. Researchers at Loughborough University’s Centre for Renewable Energy and Sustainable Technology developed a multilayer antireflection coating that reduces reflection by more than 70 percent across the wavelength range accepted by solar panels. “They improve the module power output by about 4 percent and will be low cost if manufactured in high volume," said professor Michael Walls, who devised the antireflective coating with Dr. Piotr Kaminski and Fabiana Lisco. The 300-nm-thick coating consists of four alternate layers of zirconium oxide and silicon dioxide. The materials were chosen because they are abundant and low cost. The coatings are deposited using a magnetron sputtering machine, which was developed by UK-based Power Vision Ltd. to deposit antireflective coatings on eyeglass lenses. “The AR coating has to be cost-effective and so the design is a compromise,” Kaminski said. “We want the best quality AR coating, but with inexpensive materials and as few layers as possible. Also, the whole stack should be very thin to save time in manufacturing.” Although the work is specifically aimed at improving the efficiency of thin film cadmium telluride solar cell devices, the coatings can be applied to other thin film technologies such as copper indium gallium selenide (CIGS) and amorphous silicon. The coating can also be applied to cover glass on crystalline silicon modules and third-generation devices such as organic or perovskite devices. “Each PV technology operates in a different wavelength range and it is relatively simple to accommodate this in the multilayer design for each case,” Kaminski said. The work was funded by the Engineering and Physical Sciences Research Council's Supergen SuperSolar Hub. For more information, visit: www.lboro.ac.uk