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Breakthrough Efficient, Paintable Solar Cells

Posted by CmdrTaco on from the beam-me-up-or-something dept.

An anonymous reader writes "A new solar cell material has been discovered that converts 30% of the sun's energy to electricity." Here's another solar news story. These new cells can harness infrared light which is why they are so much more efficient.

2 of 445 comments (clear)

  1. Potential != Realized by Daxton · · Score: 5, Informative

    If you check the original press release, you'll notice UT says the 30% efficiency might be realized "with further improvements in efficiency". The reporter for CTV missed that little nuance.

    --
    Sweeping statements should never be made.
  2. Re:POTENTIAL 30%, not actual by Anonymous Coward · · Score: 5, Informative

    2 comments...

    But first, my background...

    I actually read the journal paper.

    I work on related projects in graduate school, including polymer solar cells, and prior to that worked for a company developing quantum dots for other applications.

    1.) The 30% is the theoretical power conversion maximum for a solar energy conversion with a single layer device; they only got a small fraction of this. You could only get this maximum if you had a material that absorbed every photon in the theoretically correct range, every one of these photons created an electron, and every electron came out of the device -- not an easy task, and 30% is the best you could do. The reason there is a 30% maximum is simple -- the device only puts out a single voltage, corresponding to the point of longest wavelength (lowest energy) that the material absorbs. This voltage is the same for all electrons that are generated from each photon. This means all those blue photons become just like the IR photons -- they give up a bunch of energy.

    2.) The materials would be cheap. Quantum dots are not exotic. They're just little chunks of semiconductor. They are called quantum dots because their size is such that they have what are called quantum size effects. They are made from soap and metal salts. Massive production would be cheap. The polymer would be cheap to mass produce, as well. The problem is sandwiching it between electrodes -- you couldn't just paint it on without this.

    So, basically, this isn't a huge advance... It's the normal stepwise improvement. They took existing technologies that are available, combined them and hyped them up a lot.