Jul 30 2009
SRI International, an independent nonprofit research institute, and Showa Denko K.K. (SDK), a Japan-based chemical industry company in partnership with Itochu Plastics Inc. (CIPS), have achieved record-breaking results using SRI's new cavity organic light-emitting diode (COLED) technology and SDK's light-emitting polymers to produce a highly efficient light source that could one day replace incandescent and fluorescent light bulbs.
SRI's COLED device is a new OLED structure designed by Dr. Yijian Shi, project team leader and senior chemist at SRI, that uses cavities to generate up to five times greater light output compared to traditional OLED structures. In addition, SRI's new COLED device has the potential to be two times more efficient than compact fluorescent lights, which 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, 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 (a measure of light output) 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 higher 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. 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 Showa Denko, K.K.
"SRI's COLED device will bring an innovative breakthrough to the lighting industry and the world's energy conservation efforts. I am proud of what the SDK, SRI and CIPS team has accomplished in such a short period of time," said Mr. Ryuichi Komatsuzaki, president of Itochu Plastics Inc.