56.2: Analysis and Interpretation of Degradation Mechanism of OLED with p-doping Layer

We demonstrate that the new structure show an outstanding EL Lifetime that is 2 times higher than in the reference device. We explain the degradation mechanism of p‐doping layer on the charge injection in organic light‐emitting diode. Generally, p‐doping layer has the ability to reduce the interface barrier between Anode and HTL, the role of simplifying the multi‐layer. But, except of power consumption, there is not the detailed report of analyzing the degradation depending on the p‐doping efficiency which means the relative yield of charge transfer complex between p‐dopant and HTL. In order to understand the underlying cause and mechanism of degradation in OLED consisted of p‐doped system, Impedance Spectroscopy (IS) was used. Using AC with frequency sweep and DC measurement, it's possible to differentiate between bulk and interface properties and find their effect on the degradation mechanism. Using IS we will show how different factors contribute to the overall degradation mechanism, and how by changing them we can achieve the lifetime improvement.