Boffins at the
New
Jersey Institute of Technology (NJIT) have developed an inexpensive solar
cell that can be painted or printed on flexible plastic sheets.
Lead researcher Somenath Mitra, professor and acting chairman at NJIT's
Department
of Chemistry and Environmental Science, described the process as "simple".
"Someday homeowners will be able to print sheets of these solar cells with
inexpensive home-based inkjet printers," he said. "Consumers can then slap the
finished product on a wall, roof or billboard to create their own power
stations."
Harvesting energy directly from abundant solar radiation using solar cells is
emerging as a major component of future global energy strategies, but
effectively harnessing renewable energy still has many challenges.
Expensive large-scale infrastructures such as windmills or dams are necessary
to drive renewable energy sources, such as wind or hydroelectric power plants.
Purified silicon, also used for making computer chips, is a core material for
fabricating conventional solar cells. However, the processing of a material such
as purified silicon is complex.
"Developing organic solar cells from polymers, however, is a cheap and
potentially simpler alternative," said Mitra.
"We foresee a great deal of interest in our work because solar cells can be
inexpensively printed or simply painted on exterior building walls and/or roof
tops.
"Imagine driving in your hybrid car with a solar panel painted on the roof,
which is producing electricity to drive the engine. The opportunities are
endless."
The solar cell developed at NJIT uses carbon nanotubes 50,000 times smaller
than a human hair.
Just one nanotube can conduct current better than any conventional electrical
wire, and nanotubes are significantly better conductors than copper.
Mitra and his research team took the carbon nanotubes and combined them with
tiny carbon buckyballs (known as fullerenes) to form snake-like structures.
Buckyballs trap electrons, although they cannot make electrons flow. Add
sunlight to excite the polymers, and the buckyballs will grab the electrons.
Nanotubes, behaving like copper wires, will then be able to make the electrons
or current flow.
"Using this unique combination in an organic solar cell recipe can enhance
the efficiency of future painted-on solar cells. Someday, I hope to see this
process become an inexpensive energy alternative for households around the
world," concluded Mitra.
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