FRIDAY 17 OCTOBER, 2008 |
Ultra Efficient Solar Panels - Black Silicon
While solar power
come a long way, the best solar panels
the general market only convert around 15 - 20% of the sun's rays into
electricity. Silicon makes an excellent visible light detector, but it's unable
to detect other wavelengths commonly found in nature.
Eric Mazur, a physicist at Harvard University, believes an ultra-sensitive form
of silicon called black silicon could approach the theoretical limit of
converting around 30%-40% of sunlight into electricity.
The material was actually discovered by Mazur back in 1998 by accident when his
team exposed normal silicon with a very short laser pulse - one billionth of a
millionth of a second. The end result was a highly disordered surface resembling
a forest of short spikes. The resulting structure offers far more surface area
for exposure to the sun.
While textured silicon is nothing new, Mazur's black silicon is sensitive to
various wavelengths and produces an electrical response to light that is
approximately 500 times normal silicon. It's also able to absorb infra-red
radiation which makes up up around 25% of the energy coming from the sun.
The nature of black silicon also allows for the production of thinner cells and
given the global silicon shortage and consequent price increases for the
material, more solar panels can be made with less silicon, but still with
Mazur's company SiOnyx
recently unveiled the production of the first commercial-grade black silicon
wafers, but as with all new developments in the solar panel industry, it will
likely be quite some time before we'll see black silicon cells available in solar
on the general market.
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