Nichia breaks 100 lm/W barrier for a white LED
Nichia plans to commence production of white LEDs with an efficacy of 100 lm/W, at an operating current of 20 mA.
The news was confirmed by Nichia following a story that appeared on the EE Times website.
White LED manufacturers have been steadily increasing the efficacy of white LEDs in recent years. A figure of at least 70 lm/W is necessary for white LEDs to compete directly with fluorescent lights.
Previous expectations were for the milestone figure of 100 lm/W for a white LED to be reached by 2008 to 2010. However, Nichia has now adjusted its roadmap to call for a 150 lm/W device by 2007.
It is important to emphasize that the latest result was achieved for a small LED chip with a conventional drive current of 20 mA. Larger chips driven by higher currents up to 1 A produce significantly more lumens but are less efficient.
For example, Cree recently announced that its latest commercial white XLamp package produces 57 lm when driven at 350 mA, with an efficacy of 47 lm/W. Cree has also previously stated that it has achieved 100 lm/W in the lab for a 5-mm package white LED driven at 20 mA (see Cree tops 100 lm/W mark in the lab (Feb 2005).
Nichia also showed prototypes of a pendant light and a spotlight using the new white LED. Both fixtures also had an efficiency of about 100 lm/W. The prototype pendant light employed 756 white LEDs to deliver 4,536 lumens with a 45 W input. The spotlight contained 480 lumens with 4.8 W input.
Nichia intends to start sampling the 100 lm/W chip in June and to start volume production by the end of the year. The first product will be a 5-mm-diameter lamp package. Before then, an 85 lm/W white LED is expected to hit the market in April.
There wasn't a big technical jump to reach 100 lm/W, said Gen-inch Shinomiya, managing director in charge of the R&D engineering division at Nichia. "We improved our technology incrementally and steadily have reached this level. And I believe we can reach the level of 150 lm/W in the same way," he said.
"The biggest bottleneck is cost" when comparing LEDs with fluorescent lighting, said Shinomiya. If simply compared in price, a white LED costs nearly 10 times more than a corresponding fluorescent. Considering LEDs' advantages, such as a low running cost and no need for additional circuitry, the cost is still several times higher than for conventional lamps.
Nichia expects total revenue of 195 billion ¥ ($1.7 billion) for its 2005 fiscal year - see White LED price cuts reduce Nichia's sales, profits.
Nichia manufactured more than 5 billion units of GaN-based LEDs last year, and nearly 90 percent of them were white LEDs, said Noboru Tazaki, executive vice president of Nichia. The company estimates 13-15 billion GaN-based LEDs were produced globally last year; a large percentage of them were low-end products.
Nichia's mid-term business strategy calls for sales growth to about 300 billion ¥ ($2.6 billion) by 2010, with LED production doubling to 10 billion units a year.