Samsung Advanced Institute of Technology

Understanding the stability and degradation of organic light-emitting diodes (OLEDs) under working conditions are significant areas of research for developing more effective OLEDs and further improving their performance. However, studies of degradation processes by in situ non-invasive methods have not been adequately developed. In this work, tris-(8-hydroxyquinolino) aluminum (Alq₃)-based OLED degradation processes have been analyzed through the investigation of the device dispersive magneto-electroluminescence (MEL(B)) response measured at room temperature. By studying the change in the MEL(B) response during the device degradation under different external stimuli, such as exposing the device to the atmosphere and prolonged illumination by strong visible light source, we have gained insight into the microscopic spin-dependent phenomena which administrate the recombination of e-h polaron pairs in the device. We found that the device degradation leads to shorter e-h polaron lifetime, smaller dispersive parameter and broader lifetime distribution function that show increase disorder in the active layer. This study could offer a potential tool which may be beneficial for assessing degradation of OLED devices based on various active layers.