Dye-sensitized solar cells are flexible and cheap to make, but they tend to be inefficient at converting light into electricity. One way to boost the performance of any solar cell is to increase the surface area available to incoming light. So a group of researchers at Georgia Tech has made dye-sensitized solar cells with a much higher effective surface area by wrapping the cells around optical fibers. These fiber solar cells are six times more efficient than a zinc oxide solar cell with the same surface area, and if they can be built using cheap polymer fibers, they shouldn't be significantly more expensive to make.

Solar on fiber: An optical fiber (left) is covered in dye-coated zinc-oxide nanowires (closeup, right). Both images were made using a scanning electron microscope. Credit: Angewandte Chemie

The advantage of a fiber-optic solar-cell system over a planar one is that light bounces around inside an optical fiber as it travels along its length, providing more opportunities to interact with the solar cell on its inner surface and producing more current. "For a given real estate, the total area of the cell is higher, and increased surface area means improved light harvesting and more energy," says Max Shtein, an assistant professor of materials science and engineering at the University of Michigan who was not involved with the research.