Novel chip design and the balance of multiple interrelated design parameters have enabled Cree, Inc.'s Santa Barbara Technology Center to demonstrate white LEDs with efficacies greater than 65 lumens per watt at 350 mA. The results are particularly significant because they were achieved with a pre-production prototype chip using the same package used in Cree's commercially available XLamp® 7090 high power LED, rather than a laboratory device XLamp® 7090 high power LED
This achievement is based on improved output of the primary blue emitting chip, which was combined with acommercially available yellow phosphor. The results are on par with some compact fluorescent lighting systems and up to 10 times as efficient as incandescent sources.
Cree's achievement is part of a three-year project focused on demonstrating that existing white LED technology could be successfully scaled up (in terms of electrical input/optical output power) to levels suitable for general illumination applications, with superior energy efficiency. This goal requires significant improvements in such diverse areas as chip efficiency, optical design, and thermal management.
The holy grail of LED lighting has been the core efficacy metric beating other white lighting systems. This is hapenning and is a matter of time before the technology is commoditized. We are predicting the the efficacy with go up to more than 90 lm/W by the end of 2007.