Green Design

Efficient Light Source Technology

New cavity organic light-emitting diode (COLED) technology from SRI International and light-emitting polymers from Showa Denko K.K. (SDK) produce a highly efficient light source that could replace incandescent and fluorescent light bulbs.

SRI International of Menlo Park, CA is an independent nonprofit research institute, and SDK is a Japan-based chemical industry company. 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.

The SRI 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. According to SRI, this is 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.