Intematix has announced that one of its remote-phosphor optics combined with Philips Lumileds Luxeon T/TX LEDs in a technology demonstration has yielded efficacy of 203 lm/W at the light source level. The duo built the module, that at least for now will not be commercially sold, although the remote-phosphor optic and the LEDs used in the demo are readily available from the two companies to developers of solid-state lighting (SSL) products.
The demonstration relied on a rather cool CCT of 6000K that Intematix called a daylight spectrum, and that the company noted is located on the black-body curve, albeit with a CRI of 70. Certainly the cool CCT and relatively low CRI make high efficacy more easily achievable, although the accomplishment is still noteworthy.
"Remote-phosphor architectures lower cost, increase efficacy, and improve light quality in many of the consumer, commercial, industrial, and outdoor area lighting applications commonly deploying LED technology today," said Yi-Qun Li, CTO of Intematix. "This result is a significant step along our innovation roadmap for phosphor solutions."
Last year we had dueling articles from Cree and Intematix on the merits of remote-phosphor technology. We also had a recent feature in which Xicato asserted the color consistency advantages of remote phosphor.
Of course, the obvious question is why did Intematix and Lumileds decide to make a public announcement about the demonstration in module form, when apparently neither will offer the module for sale. Senior director of strategic marketing Julian Carey said, "Intematix remains a phosphor solutions maker. The module was developed as a technology demonstration to show how much performance can be obtained using remote-phosphor solutions."
Lumileds certainly welcomed the chance to demonstrate the blue-pump LEDs in the Luxeon T/TX family that deliver wall plug efficiency of 76%. "This marquee performance simplifies a wide variety of thermally constrained applications such as 100W A19 bulbs and high-lumen candle lamps, and enables downlights with the highest efficacy in the industry," said Jy Bhardwaj, senior vice president of R&D at Philips Lumileds.
Still, the question remains as to how popular remote-phosphor technology will be going forward despite any efficacy advantage. Lumiled's parent Philips Lighting has moved away from remote phosphor despite success with designs such as the L Prize lamp. But Intematix does have new optics that have a near-white look in the off state.
"We expect more of our customers to come out with systems that have high performance using our remote phosphor solutions," added Carey. Lumileds Bhardwaj said, "We're very proud of this landmark performance of 203 lm/W as this was achieved using our latest commercially available LED technology and Intematix's remote phosphor."