EFFICIENT PHOSPHORESCENT OLEDS BASED ON VACUUM DEPOSITION TECHNOLOGY

Abstract

Organic light emitting devices (OLEDs) are viewed as a potential next generation display and lighting applications. Phosphorescent OLED technology, with its inherently high efficiencies, represents the best opportunity to meet the challenging requirements of display and lighting applications. Thereby, we demonstrate high-efficiency organic light-emitting diodes by incorporating a double emission layer {i.e. both doped with the green phosphorescent dye tris(phenylpyridine)iridium [Ir(ppy)3]} into p-i-n-type device structure based on vacuum deposition technology. The intrinsic and doped transports layers are formed using a high vacuum controlled co-evaporation deposition technique. These have been very successful in reducing the operational voltages and increasing the power efficiency. A peak power efficiency of 77 lm/W and an external quantum efficiency of 19 % are achieved at 100 cd/m2 and at an operating voltage of 2.65 V.