Professor Zhong Lin Wang used zinc oxide nanostructures grown on optical fibers and coated them with the dye-sensitized solar materials. The prototype flexible solar fibers are about 20 cm long, although they can be made much longer. One end of the fiber faces the sun, and as photons enter the fiber, they’re absorbed along its length. In fact, the longer the fiber, the better, since that gives the light more of a chance to be absorbed. “In each reflection within the fiber, the light has the opportunity to interact with the nanostructures that are coated with the dye molecules,” Professor Wang explained. “You have multiple light reflections within the fiber, and multiple reflections within the nanostructures. These interactions increase the likelihood that the light will interact with the dye molecules, and that increases the efficiency.”
Right now Professor Wang admits that the current version of his solar energy fibers is not very efficient at only 3.3%, but expects to quickly get up to 7 or 8% after some surface modifications. Other changes to further boost efficiency will include more efficient methods for collecting the electrons and a change to a titanium oxide surface coating. He also wants to change from quartz optical cable to a much cheaper polymer fiber to further reduce costs. Ultimately, Professor Wang feels that his solar fibers can be used in many places where a traditional solar panel array wouldn’t be practical.