Nanowires may provide highly efficient lights

March 24th, 2008 - 2:32 pm ICT by admin  

Melbourne, March 24 (ANI): Nanotechnology researchers at Sweden-based Lund University are trying to develop devices that do not emit as harsh a light as existing LEDs, and that are more efficient and longer lasting.

Professor Lars Samuelson, who is leading the research project, is hopeful that such devices will be available in a few years.

“We can really make the three colours - red, green and blue - with this technology and get warm LEDs,” ABC Online quoted Samuelson, who presented his research at the recent International Conference On Nanoscience and Nanotechnology in Melbourne, as saying.

The multiple crystalline semiconductor layers used in conventional LEDs which are used in small applications like torches, bicycle lights, and reading lamps emit light when a current passes through them, and convert 30 per cent of the electricity into light.

A reason for not using conventional LEDs on a larger scale is the fact that defects in the crystal structure of the semiconductors limit their efficiency when scaled up.

“Even the commercial LEDs you buy today for your flashlight, for instance, have 10 million defects per square centimetre,” said Samuelson, of the university’s Nanometer Structure Consortium.

Now, he and his colleagues have devised a way to created defect-free LEDs.

Samuelson says that millions of thin nanowires grown from gallium arsenide and indium gallium phosphate each two micrometers tall and less than 200 nanometres in diameter produce “highly perfect structures”.

He believes that such LEDs can last longer, and be useful in large-scale home and office lighting.

The researcher also says that the new technology offers an efficiency of around 50 per cent, more efficient than the existing four per cent and 25 per cent efficiencies of incandescent or fluorescent lighting respectively.

Samuelson also says that nanowire LEDs are brighter than existing LEDs, and can emit light more easily to their surrounds. Nanowire LEDs can also be tuned to give warm colours, he adds, by adjusting the concentration of different elements in the crystalline structure.

He has also revealed that he is involved in a start-up company to commercialise large-scale LED lighting within the next three years. (ANI)

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