The race towards better, more affordable solid state lighting is heating up quickly. The U.S. government has sponsored a $20M USD prize for the first team of researchers to come up with solid state lighting that meets a strict set of standards. New research has finally helped to eliminate the LED droop typically associated with the higher currents needed to provide greater efficiencies.
Now a team at Cambridge University may be close to having a winning design on their hands, perhaps for the L Prize, if they're eligible, and for the consumer market. The university has produced a new design which costs a mere $2.85 USD and despite being the size of a penny, produces similar light to a fluorescent bulb while lasting over four times as long with a lifetime of 60 years.
The new design triples fluorescent bulb efficiency and is 12 times more efficient than incandescent designs. Also, it’s capable of instantaneous illumination, so the light lag associated with fluorescent bulbs may soon be a thing of the past.
If installed across all of Britain, the researchers estimate that it could cut the country's lighting portion of the energy budget from 20 percent to 5 percent a year. The U.S. could muster a similar 10 percent drop with the design, according to recent DOE estimates. The new bulbs last 100,000 hours and unlike other "eco" bulbs, they contain no mercury, a substance that can cause brain damage in humans. They also don't flicker, while other green designs do, something that's been blamed for triggering epileptic fits.
Officials say the new design could cut 40 million tons of carbon emissions in Britain alone. Britain recently stopped restocking certain incandescent bulbs in stores. The new design relies on a specially formulated gallium nitride semiconductor, which builds on previous LED work. It is brighter than traditional designs and relatively cheap from a chemical perspective, compared to more exotic chemistries.
The British researchers managed to make the LEDs even more affordable by growing them on silicon wafers instead of on sapphire wafers, the traditional method of production. This makes them at last cheap enough for the consumer market. Growing the LEDs on silicon was assisted by a number of advances at other U.S. and European research institutions.
While some designs take decades to reach the market, Cambridge's design is already being prototyped and readied for production. RFMD in County Durham, England is the first manufacturer to jump at the opportunity to mass produce and ship the high-performing LED bulbs.
Professor Colin Humphreys, head of the team at Cambridge states, "This could well be the holy grail in terms of providing our lighting needs for the future. We are very close to achieving highly efficient, low-cost white LEDs. That won't just be good news for the environment. It will also benefit consumers by cutting their electricity bills. It is our belief they will render current energy-efficiency bulbs redundant."