More Efficient Solar Cells Made From Carbon Nanotubes
By September 21st, 2009Monday, September 21, 2009 18:04 on
Scientists from the Cornell University have created the basic element of a solar cell made from carbon nanotubes, that proves to be more much more efficient at transforming the energy from the sun into electricity.
The biggest challenge for the scientists researching solar technology today is to find a competitive substitute for silicon. We find it in computers, on solar cells, but it seems the element has been pushed to its limits. The boundaries have been reached as silicon transistors have been shrinked at minimum and solar cells made from monocrystalline silicon doesn’t prove to be the best solution.
So, in the search for new materials, researchers, led by Paul McEuen, a physics professor at Cornell, have found that building a solar cell from a single carbon nanotube, called a photodiode, can convert the light to electricity in a very efficient way, in which the electrical current flowing is multiplied. With an approximate size of a DNA molecule, the cylindrical-shaped nanotube was wired between two electrical contacts, one negatively and one positively charged.
One more exciting thing they discovered was that by using the “left-over” energy from the light electrons could “multiply”, to create more electrons, thus producing more electricity, forming almost a perfect photovoltaic cell. Today’s silicon solar cells, on the other hand, lose the excess energy in the form of heat and don’t use it to create more electricity, like the nanotube could do.
The next big step is to use this technology on a bigger scale, while keeping the efficiency as high as in the beginning and the costs at a suitable level.
Source: Cornell University
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