The white LED, containing a 1 x 1 mm chip, had an efficacy of 161 lm/W, which is the highest value reported in the industry to date.
The device had an output of 173 lumens, and a color temperature of 4689K. The tests were conducted under standard LED test conditions (meaning an instantaneous rather than steady-state measurement) at a drive current of 350mA, at room temperature.
It is crucial to remember that this level of performance is not yet available in production LEDs. However, Cree says that it is shipping millions of 100+ lumen lighting-class XLamp LEDs.
Cree’s announcement follows similar results that have been publicized in recent months by Philips Lumileds and Osram Opto Semiconductors (see LED chips set new R&D records).
Lumileds’ results were 140.1 lm/W and 138 lm, while Osram’s were 136 lm/W and 155 lm, for comparable devices. However, the actual values are less important than the fact that all these companies (and others) continue to demonstrate continued improvement of LED performance, which will gradually filter through into production devices.
John Edmond, Cree co-founder and director of advanced optoelectronics, said "Cree is inventing, commercializing and delivering LED lighting innovations that aim to obsolete the energy-inefficient light bulb," said.
"Our advances in brightness and efficacy come from a focus on end-to-end innovation that can enable LED lighting to address growing numbers of lighting applications while saving energy, saving money and helping to protect the environment."
Meeting industry’s demand
In related news, Lumileds issued a press release this week to state that it has delivered tens of millions of Luxeon Rebel power LEDs, the vast majority of which are warm, neutral and cool white in color.
Lumileds said that it has “virtually unconstrained capacity” and ability to deliver its most powerful and efficient illumination-grade products, including those that deliver 100 or more lumens and efficacy greater than 90 lm/W.
The purpose of the press release appears to be to emphasize the importance of repeatable performance and availability; “New solid-state lighting applications are only made possible with a sustainable supply of power LEDs at specific and repeatable color temperatures,” said the company. In turn, this enables luminaire designers to produce “consistent color and uniform light output from luminaire to luminaire.”