Published in Physics World, 21 Apr 2011
Physicists in the US believe that it is possible to generate solar power without solar cells. Their “optical battery” idea, which would involve performing the energy conversion inside insulators rather than semiconductors, could make for a far cheaper alternative energy source than existing solar-cell technologies.
In conventional solar cells, electricity is generated by simple charge separation. The semiconductor absorbs a photon of sunlight, knocking a negative electron into the material’s conduction energy band and leaving a positive hole in its place. With these two charges separated, a voltage is produced from which power can be drawn. […]
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