Study may lead to less expensive consumer lasers and LEDs

Jul 11, 2012

(Phys.org) -- A recent theoretical study by a University of Waterloo doctoral candidate in nanotechnology engineering suggests that manufacturers may one day make lasers and LEDs out of silicon, with the potential to significantly lower their price.

Daryoush Shiri says that making lasers and () from bulk , one of the most abundant minerals on earth, has been a longtime goal of the photonic engineering community. But while the cost of silicon is low, it suffers from an inherent electronic property called indirect bandgap that hinders the from this material. As a result, lasers are currently manufactured using other, more expensive materials.

"Extensive that involved first-principle quantum mechanical and other studies proved that silicon nanowires show dramatic changes of light emission properties when we apply ," said Shiri.

His findings were recently published in Scientific Reports, a journal of the Nature Publishing Group. Shiri¹s research shows that by stretching or compressing silicon nanowire, you can induce significant change in its light emission capabilities. Passing an electrical current through the device in its strained state leads to population inversion, which means that electrons are ready for light emission. Once the strain is removed, the electrons release their energy as packets of light, the central principle of lasing. Shiri points out that this mechanism for lasing is unique to silicon nanowires and it is not achievable in bulk silicon. The colour of light emitted can be controlled both by strain and using nanowires with different diameters.

Collaborating with a lab with the capability of fabricating the silicon nanowires is the next step. Shiri would like to see the tiny whisker-like silicon structures reduced from the typical 10 nanometers to three to five nanometers. By reducing the diameter of the nanowire, electrons have a better chance of giving off their energy as light. He expects it to take between two to five years of experimentation until nanowires are fabricated to the ideal scales.

Consumers see lasers in everything from supermarket barcode scanners, printers, to CD or DVD players. LEDs are used in car headlights, lamps, and other consumer products.

Shiri collaborated on his research with his doctoral thesis supervisors C.R. Selvakumar, an electrical and computer engineering professor at Waterloo; Anant Anantram, a former engineering professor at Waterloo who is now at the University of Washington-Seattle; and Amit Verma, a professor at Texas A & M University-Kingsville.

Explore further: Protons fuel graphene prospects

More information: The paper can be downloaded at www.nature.com/srep/2012/12061… /full/srep00461.html

Related Stories

Nanowires offer opportunities for improved LEDs

Jul 01, 2011

Researchers from Dutch FOM Institute AMOLF, together with colleagues from Philips Research, Eindhoven University of Technology and Delft University of Technology, have made special nanostructures that could ...

3-D view of 1-D nanostructures

Jan 06, 2012

Semiconductor gallium nitride nanowires show great promise in the next generation of nano- and optoelectronic systems. Recently, researchers at the McCormick School of Engineering have found new piezoelectric ...

Recommended for you

Protons fuel graphene prospects

14 hours ago

Graphene, impermeable to all gases and liquids, can easily allow protons to pass through it, University of Manchester researchers have found.

Cooling with the coldest matter in the world

Nov 24, 2014

Physicists at the University of Basel have developed a new cooling technique for mechanical quantum systems. Using an ultracold atomic gas, the vibrations of a membrane were cooled down to less than 1 degree ...

Magnetic fields and lasers elicit graphene secret

Nov 24, 2014

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have studied the dynamics of electrons from the "wonder material" graphene in a magnetic field for the first time. This led to the discovery of ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

that_guy
not rated yet Jul 11, 2012
2-5 years of experimenting.

Translation, there's a 50/50 between never happening, and 5 years experimentation another 5 years to commercialize.

On another note: assuming this is successful, it has a lot of merit for electronics with integrated lasers and on chip laser communication.

However, for LED lighting (Like lightbulb replacements) - What is the cost portion of the LED element versus the cooling hardware? could this conceivably make a real dent in production cost in that area?
El_Nose
not rated yet Jul 16, 2012
LED's are inherently very low heat producing elements. However, in producing LED bulbs there are liquid filled LED's that have an organic liquid inside that absorbs heat and radiates it away through the bulb surface.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.