Analysis of Thermal Stress Effect on Blue Phosphorescent Organic Light-Emitting Diodes for Device Stability

Abstract

We demonstrated the influence of external thermal stress on blue phosphorescent organic lightemitting diodes. We fabricated devices using the same structure and materials, including a low glass transition temperature material, and the devices were then annealed at 50, 60, 70, and 80 degrees C to compare their properties to those of pristine device. In this study, we observed a decrease in the current density-voltage-luminance and lifetime due to thermal stress, and we also used various analysis methods, such as impedance spectroscopy, to obtain detailed measurements to determine the degradation mechanisms of the device.