Interplay between ambient and exciton-induced degradation in organic light-emitting devices

Organic light-emitting diode (OLED), albeit is currently used in consumer electronics, still faces challenge with its limited performance stability. The degradation mechanisms that limit the lifetime of OLEDs can generally be separated into two categories: ambient and intrinsic. Much research has been devoted to understanding thus limiting these degradation mechanisms. However, surprisingly, there has been little work on how ambient and intrinsic degradation affect each other. In this work, the interplay between the ambient and intrinsic (more specifically exciton-induced) degradation is studied by comparing the effects of four degradation schemes, namely, no ambient or exciton-induced, ambient only, exciton-induced only and ambient and exciton-induced degradation on device lifetime. The results show that there is no interplay between ambient and exciton-induced degradation. Furthermore, it is evident that no photo-oxidation is present during ambient and exciton-induced degradation.