3D Photovoltaic System Hides Solar Cells from View

Scientists at the Georgia Institute of Technology (Georgia Tech) announce the completion of a new type of solar cells, one that may not need to be located on traditional surfaces, such as rooftops. The innovation makes use of nanostructures grown directly on optical fibers, and coated with light-sensitive dyes. This approach allows for the creation of three-dimensional photovoltaic systems that may be placed in locations where conventional solar panels would simply not do the job.

“Using this technology, we can make photovoltaic generators that are foldable, concealed and mobile. 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 Georgia Tech School of Materials Science and Engineering Regents Professor Zhong Lin Wang shares. A detailed explanation of the new system's basic operating principles appears in the October 22 issue of the renowned scientific journal Angewandte Chemie International.

Some of the main supporters of the new line of research include the Defense Advanced Research Projects Agency (DARPA), the KAUST Global Research Partnership, and the US National Science Foundation (NSF). “In each reflection within the fiber, the light has the opportunity to interact with the nanostructures that are coated with the dye molecules. 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,” Wang adds.

Dye-sensitized paint is an extremely versatile solution for producing electricity out of sunlight. It is very cheap to manufacture, as it does not involve a very complex production process, and is also very robust, which makes it suited for such applications. However, it converts energy at a lower rate than silicon-based photovoltaic materials do. But this is where the nanostructures come in. They help increase the surface of the paint, and thus boosts its efficiency beyond that of silicon-based cells.

“This will really provide some new options for photovoltaic systems. We could eliminate the aesthetic issues of PV arrays on building. We can also envision PV systems for providing energy to parked vehicles, and for charging mobile military equipment where traditional arrays aren't practical or you wouldn't want to use them,” Wang concludes.