Research on the influence of ultraviolet radiation on OLEDs and the luminance attenuation model of light aging

We investigated the degradation performance of organic light-emitting diodes (OLEDs) under different ultraviolet (UV) irradiation intensities and demonstrated that the stretched exponential decay (SED) model, applicable in electrical aging, is also suitable for describing the luminance-time curves in photoaging. In this way, OLED lifetime acquired at low UV illumination could be fitted with that obtained at high illumination. We also demonstrated how UV radiation affects the interface at the ITO/hole transport layer, which led to its degradation. This was elucidated through changes in the mobility of single-carrier devices and XPS characterization of the films before and after UV irradiation. These findings reveal the external behavior and internal mechanism of OLEDs in light aging, providing a reliable research direction for enhancing the stability of organic electronic devices.