OLED Devices with Dinuclear Copper Compounds

Institution: University of Rochester

Summary
This is an organic light emiting diode (OLED) with a unique light emitting layer having a dinuclear copper compound concentration in a host material.

Advantage
Performance limitations in OLED devices have represented a barrier to many applications. The choice of host material in the light emitting layer is important for the optimal operation of the electroluminescent device. A worthwhile host material is one from a class of compounds that contain a carbazole substituent. This device also has an exciton blocking layer adjacent to the light emitting layer and is made of a material that has a triplet energy level which exceeds that of the phosphorescent emitter and is greater than 2.5 eV. The total combined thickness of the organic layers is less than 500 nm. This device exhibits light emissions having desirable efficiency and color. Most light-emitting materials that have been described for OLED devices emit light from their excited singlet state by fluorescence and receive their energy from the only 25% of the singlet excitons created in the device. The remaining triplet excitons cannot readily transfer their energy to the singlet excited state of a dopant and therefore are lost, leading to low device efficiency. Triplet excitons can transfer their energy to a dopant if it has a triplet excited state that is low enough in energy. The dopant in this invention is chosen for this characteristic. Its triplet state is also emissive which can produce light by phosphorescence. Thus, by the proper choice of the host and the dopant in the light-emitting layer of this invention, it is possible to collect energy from both the singlet and triplet excitons created in an OLED device and produce highly efficient phosphorescent emission.

Inventor
Richard Eisenberg

Category
Materials:OLEDS/Polarizers

Contact Information
Jack Fraser
jfraser@ott.rochester.edu
http://www.urmc.rochester.edu/technology-transfer/find-technologies/index.cfm?TechnolID=793498