Abstract
One of the key reasons for OLEDs’ degradation is associated with the degradation of the organic emission layers and their interfaces mainly within the electron-hole recombination zone, where the exciton density is high. As a result, the energy density is high as well, which can result in a high probability of degradation. The spatial profile of the recombination rate within the emission layer is determined by charge carrier mobility, relative permittivity and mainly by energy barriers at the interface of adjacent layers. In turn, the field dependence of charge carrier mobilities leads to a change in their spatial profiles and, consequently, to the influence of layer thickness on the recombination rate profile. In this work, using drift-diffusion numerical model with direct recombination approximation and Poole-Frenkel model of charge carrier mobility, the impact of layers thickness proportion on the charge carrier recombination profile have been investigated.