White organic light emitting diodes (OLEDs) have become well recognized as an important candidate for future lighting products. However, outstanding challenges with respect to efficiency and degradation processes remain. Previous work on tandem OLED technology has produced devices with increased, brightness, efficiency, and lifetime. However, it was found that the interconnecting layer is crucial to device operation and requires delicate handling, as well as evaporation or sputtering techniques. Carbon nanotube sheets, which have excellent electrical and optical properties, could be used as alternative interconnecting layers. Also, the use of carbon nanotube sheets could simplify the fabrication process. Therefore, this project will utilize a carbon nanotube hole-injecting interlayer in the development of bright, high efficiency white tandem OLEDs. The proposed concept involves a parallel connection of the electroluminescent units in the tandem configuration. The parallel configuration reduces operating current and increases lifetime.
Commercial Applications and Other Benefits as described by the awardee: Bright, high-efficiency white tandem OLED can play an important role in the multi-billion dollar lighting and display market
