Advance in Solar Cell Coating Greatly Boosts Efficiency, Researchers Say

American researchers say they have invented a new anti-reflective coating for solar panels that absorbs nearly all the sunlight striking from any angle. Scientists at Rensselaer Polytechnic Institute in Troy, New York say their super-thin coating enables photovoltaic cells to absorb 96 percent of solar energy, compared to about 67 percent using current cells. The new coating features two major advances, the researchers say: It captures more colors of the solar spectrum, and it absorbs light from all angles. Reporting in the journal Optics Letters, lead researcher Shawn-Yu Lin said the coating is composed of seven layers stacked in such a way that each improves upon the anti-reflective properties of the layer below, trapping light from all angles. The coating, pictured at left, is made up of tiny silicon dioxide and titanium dioxide nanorods, at top, positioned at oblique angles. Currently, state-of-the-art solar arrays move automatically to track the sun’s arc throughout the day, but Lin’s discovery would eliminate the need for mechanized movement, which also would improve efficiency.