Semi-Transparent, Color Photovoltaics Could Enable Energy-Harvesting Billboards

Researchers at the University of Michigan College of Engineering have invented colorful, see-through solar cells that enable 'stained' glass windows and even shade that makes electricity. Engineer Jay Guo, who devised the cells, says they have the potential to vastly broaden the use of the energy source. They are made with a technique that borrows from conventional inorganic solar cells and more up-and-coming organic cells. Their color is not derived from dyes, but rather from adjusting the thickness of their semiconductor layer to reflect certain wavelengths of light. "Today, solar panels are black and the only place you can put them on a building is the rooftop," says Guo. He envisions them on the sides of buildings, as energy-harvesting billboards and as window shades. "We think we can make solar panels more beautiful - any color a designer wants. And we can vastly deploy these panels, even indoors."