New, Stable Cathode Materials for OLEDs

72603B03-I Many of the cathode materials currently in use in OLEDs are metals, such as Mg and Ca and alloys. In many cases, the migration of these metals to form rough interfaces and hot-spots has lead to reduced lifetimes of the devices. There is a need to develop highly stable cathode materials that have low work function, can be nondestructively coated over large areas as flexible thin films on the organic emitting materials, and possess hermetic sealing properties to promote long device life. This project will develop a new class of cathode materials that have low work function and are highly stable. This class of materials, which can be coated on organic materials as thin films, will allow work function modification, and will be highly dense to resist the penetration of both oxygen and water. In Phase I, the deposition conditions for producing these conducting, low-work-function films will be determined. Subsequently, thin films will be deposited on OLED devices and their effectiveness as cathodes compared with conventional cathode materials. Commercial Applications and Other Benefits as described by awardee: These cathode materials should become an important enabling technology to realize the potential of OLEDs on flexible polymeric substrates. Applications include both illuminated displays and lighting applications.