http://www.newscientist.com/article/mg20427366.500-lotus-leaf-effect-ramps-up-the-power-of-solar-cells.html Lotus leaf effect ramps up the power of solar cells
25 November 2009 by Paul Marks
SOLAR cells have an unfortunate habit of reflecting back much of the light that hits them, rather than converting it into electricity. A technique that peppers the cells' surface with nanoscale domes could curb this tendency and improve efficiency by as much as 25 per cent.
To ramp up the proportion of light solar cells converted into electricity, Yi Cui of Stanford University in California has focused on ensuring that more light gets through the layers of silicon.
Low-power solar cells in devices such as wristwatches and calculators are made of amorphous silicon, which converts light in the range of 400 to 800 nanometres into electricity. However, around 35 per cent of light is reflected back into the sky.
Cui's team cut this to a mere 6 per cent by depositing the solar cell's usual sandwich of layers onto a quartz base, studded with an array of 100 nm-wide cones set at 450-nm intervals (Nano Letters,
http://dx.doi.org/10.1021/nl9034237">DOI: 10.1021/nl9034237).
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