Organic LEDs produce saturated, bright-red light-emission spectra
Researchers at the Optical Sciences Center of the University of Arizona have fabricated efficient organic-light-emitting devices with saturated red-light-emission spectra.
Researchers at the Optical Sciences Center of the University of Arizona have fabricated efficient organic-light-emitting devices with saturated red-light-emission spectra. The interesting aspect of these devices is that they are hybrids and use a more stable cathode such as aluminum (Al) instead of calcium or magnesium. Current state-of-the-art devices, based on the phosphorescent dopant platinum octaethylporphyrin and magnesium silver alloy cathode, emit saturated red light with luminance of about 1 cd/m2 at an external efficiency of 5.6%. These same devices also have an external efficiency of 2.2% at a luminance level of 100 cd/m2, a level more suited for display applications. The hybrid devices with Al cathode allow for the emission of saturated red color and have external quantum efficiency approaching 9% at forward light output of about 14 cd/m2. At about 100 cd/m2, these devices have an external quantum efficiency approaching 7%. More optimization is also underway to push the performance even higher.
About the Author
Neil Savage
Associate Editor
Neil Savage was an associate editor for Laser Focus World from 1998 through 2000.