Sharp Red Organic Light-Emitting Devices with Enhanced Efficiency

The fabrication of efficient and bright red light-emitting organic electroluminescent devices based on Eu-complex, having narrow spectral width, is achieved by enhancing the electron injection process through the use of LiF/Mg cathode. Devices with external quantum efficiency exceeding 1% and light output higher than 320 cd/m2 are presented. While the external quantum efficiency at 100 cd/m2 is comparable, the luminous efficiency is 2.6 times higher than that of the recent state-of-the-art devices based on the phosphorescent dye PtOEP.