Researchers claim breakthrough in LED technology

Posted by Emma Woollacott

Menlo Park, CA - A new, highly-efficient light source has been developed that could one day replace incandescent and fluorescent light bulbs.

Non-profit research institute SRI International and Showa Denko KK (SDK), a Japan-based chemical company, have combined SRI’s new cavity organic light-emitting diode (COLED) technology and SDK’s light-emitting polymers.

SRI’s COLED device is a new OLED structure that uses cavities to generate up to five times as much light output as traditional OLED structures. The developers say it has the potential to be twice as efficient as compact fluorescent lights, which also contain mercury and present a disposal problem.

"With our new cavity design, SRI has significantly increased the efficiency of OLED devices," said Philip von Guggenberg, director of business development at SRI International. "These new results validate our strategy of focusing on new device architectures to improve the performance of OLED devices."

A combination of SDK’s light-emitting polymer materials and SRI’s COLED technology has enabled researchers to achieve an output of 30 lumen per watt for blue light — higher than any other reported polymer OLED result. For green light, the team has achieved more than 80 lumen per watt — about three times more than a traditional OLED.

To produce white light that is acceptable for illumination, a mix of red, green, and blue light is required — with blue being the most technically challenging to produce. But the results from SRI and SDK’s research point to the feasibility of producing a white light source of sufficient quality at low cost.

"Showa Denko is excited about this promising development. With SRI’s help, we expect to make this technology available to the lighting industry as early as 2010," said Mr. Kyohei Takahashi, president of SDKK.