Showa Denko K.K. (SDK) has developed new, efficient, coated phosphorescent-polymer-based OLEDs. The new devices achieved about 40% in light output (the quantity of light emitted from light source, divided by electric power consumed.) - which they claim is the highest level in the world. The efficiency is 30 lm/W, and the lifetime is approximately 10,000 hours.
SDK says that OLED made by coating is attracting keen attention because it consists of a few layers formed by coating polymer without the use of vacuum, providing the opportunity for substantial cost reductions and for the production of large
area-emission panels in the future.
While the conventional-type device has a structure of cathode, emitter, anode, and glass substrate, the new structure has introduced a layer of dielectric/heat conductor that adjusts reflection of light. The new layer helps reduce the percentage of light trapped in the device, improving the light output. The dielectric/heat conductor layer, having high heat dissipation efficiency, prevents heat deterioration of the emitter, prolonging the device life.
SDK is working with SRI International, a non-profit US research organization and Itochu Plastics, of Japan, to promote the development of coated phosphorescent-polymer-based OLEDs for early commercialization in the OLED lighting market.
