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. The new structure 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.

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 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.