From Richard Corkish, University of New South Wales
Sydney
I hope the researchers working on devices that could possibly halve the
wavelength of light at which electrical energy can be obtained
(“Your flexible friend”, 8 November, p 42)
will keep in the backs of their minds a more
important application than increasing the information density of CDs.
If it was cheap, of large area and high efficiency, such a device could help
overcome one of the fundamental problems of photovoltaics—the difficulty
in making use of photons whose energy is smaller than the bandgap energy of the
semiconductor of which a solar cell is made. Shifting these photons above the
bandgap would convert a problem into an asset.
