General Illumination Using Dye-Doped Polymer LEDs
Investigating Organization
Intelligent Optical Systems
Principal Investigator(s)
Steven Cordero
Subcontractor
None
Funding Source
Small Business Innovation Research
Award
DOE Share: $99,998
Contract Period
7/1/02 - 6/30/03
New illumination technologies should be cost effective and have an acceptable color-rendering index (CRI). OLEDs, as broadband white light sources, are one such technology. A major advancement in the development of OLEDs has been the implementation of phosphorescent dyes as the emitting species, which has prompted large device enhancements to both monochrome and broadband OLED systems.
These advances have also created opportunities to enhance lighting efficiency by mating electro-phosphorescence with novel polymers. Intelligent Optical Systems (IOS) is pursuing this pathway, which is expected to result in easy-to-process polymer materials. These materials have exceptional properties, and are an inexpensive and efficient general illumination lighting source. This methodology will allow polymer light emitting devices (PLEDs) to obtain the outstanding efficiencies of small molecule-based devices.
IOS has successfully demonstrated a white light source for general illumination that uses the triplet emission from one or more dyes embedded in a novel polymer matrix. Using this approach, the devices maximize the conversion of charge-to-light. The methodology is unique because the polymer matrix allows the use of highly efficient phosphorescent dyes as emitters within the device architecture. The researchers expect that external device efficiencies will be greater than 4%, while maintaining excellent color rendering quality and high brightness.
In the first phase of the project, IOS demonstrated the feasibility of producing PLEDs significantly more efficient than existing fluorescent-based white devices. Future research will involve strengthening and enhancing the PLED technology by studying performance degradation issues. Material purity, device fabrication pathways, and device structural design will be researched. This research will be instrumental in improving the device fabrication capabilities, material analysis, and overall lighting knowledge needed for this technology to improve solid state lighting efficiency.