RELIABILITY AND DEGRADATION OF ORGANIC LIGHT-EMITTING DEVICES

We present a simple encapsulation technique for organic light emitting devices OLEDs). By studying the degradation of a population of OLEDs, we show that the lifetime of encapsulated devices is increased by more than two orders of magnitude over that of unencapsulated devices. In both cases, degradation is primarily due to the formation of nonemissive regions, or dark spot defects. By studying the structure and evolution of the dark spots, we infer that the growth of electrode defects limits device lifetime. Hermetic packaging of OLEDs is essential if they are to be used in commercially viable flat panel displays. © 1994 American Institute of Physics.