Researchers at New Jersey Institute of Technology (NJIT) have developed very cheap solar cell that can be painted or printed on flexible plastic sheets. "The process is fairly simple," said lead researcher and author Somenath Mitra, PhD, professor and acting chair of NJIT’s Department of Chemistry and Environmental Sciences. "Someday homeowners will even be able to print sheets of these solar cells with inexpensive home-based inkjet printers. Consumers can then slap the finished product on a wall, roof or billboard to create their own power stations."
The production of cells is easy. At the production line there is roll-to-roll reactors, much like newsprint speeding through a press.
The panels are quite light and flexible as well, which is very usefull in the space, military and recreational markets. For standard applications, the solar cells can also be encapsulated into a more traditional rigid structure.
By being flexible, the solar cells can be adjusted to different surfaces like roofing applications for building integration, and for airships and balloons.
The solar cell sheets are created by depositing copper-indium-gallium-diselinide, which the IEC scientists call CIGS, on a 10-inch wide polymer web, which is then processed into the flexible solar cells. CIGS solar cells are currently the only thin-film technology that has achieved efficiencies comparable to silicon solar cells, presently the standard of the industry.
However, IEC has evaluated the quality of CIGS on the molybdenum-coated web by characterizing the uniformity of the film. Researchers found that average solar cell conversion efficiencies of 10 percent were achieved.
Tthin-film CIGS-based solar cells have a multi-layer structure stacked on a substrate, in this case a high-temperature polyimide substrate that is coated with molybdenum, CIGS, cadmium sulfide, zinc oxide and indium tin oxide.
“All the component films of this structure can easily be processed on flexible substrates,” Eser said, adding, “In fact, CIGS is the most difficult layer because of high substrate temperature and thermal deposition from four different elemental sources, since this process results in the best performing solar cells.”
Source: Science Daily
