Scientists in the Georgia Tech School of Materials Science and Engineering have developed a cheaper, more efficient flexible solar cell by using fiber optics and zinc oxide. These solar cells won’t replace large silicon based solar arrays in the near future but they could change the way solar energy is collected on buildings and on the move.
Zhong Lin Wang, a Regents professor in the Georgia Tech School of Materials Science and Engineering, has been working with his research team of Benjamin Weintraub and Yaguang Wei to develop a three dimensional photovoltaic system. Their system allows solar generators to be tucked away out of sight rather than mounted on the roof.
Using this technology, we can make photovoltaic generators that are foldable, concealed and mobile,” said Zhong Lin Wang… “Optical fiber could conduct sunlight into a building’s walls where the nanostructures would convert it to electricity. This is truly a three dimensional solar cell.”
The process begins with an optic fiber like the kind used by telephone companies for transmitting information. The optic fiber is modified by eliminating the cladding layer and adding a conductive coating. Then they grow zinc oxide nanowires around the fiber. The nanowires sticking out from the fiber “like the bristles of a bottle brush,” are “then coated with the dye-sensitized materials that convert light to electricity.”
Sunlight entering the optical fiber passes into the nanowires, where it interacts with the dye molecules to produce electrical current. A liquid electrolyte between the nanowires collects the electrical charges. The result is a hybrid nanowire/optical fiber system that can be up to six times as efficient as planar zinc oxide cells with the same surface area.
Wang wants to try using a different type of optic fiber and titanium oxide to build the nanowires as ways to reduce the cost of the solar cells and improve the efficiency.
These solar cells would be cheaper and less conspicuous than the flexible solar cells being used in solar jackets, solar bags and portable solar devices, making them more affordable for the rest of us.