Demonstration of macroscopic OLED simulation including exciton transport

UTV will extend its continuum transport code based on the drift-diffusion approximation to include transport of both singlet and triplet excitons. State-of-the-art mobility and density of states models appropriate for organic materials will be used for electron and hole transport, whereas the exciton models will be based mainly on results from KMC. Key model parameters like recombination rate parameters, diffusivities or exciton quenching will be obtained from ab-initio and KMC methods (see Task 3.2) using a parametric multiscale approach. An accurate description of energy alignment and charge injection at metal-organic and organic-organic interfaces will be achieved by coupling the drift-diffusion models to microscopic transport models based on the non-equilibrium Green’s function formalism used at CNR. The complete transport model will be applied in particular to 3D OLED structures. This will allow to assess the effect of spatial inhomogeneity like thermal hot-spots due to polaron-triplet quenching (see Task 3.4). The tool will also be equipped with suitable degradation models in order to simulate the temporal evolution of device performance and stability. The developed model will be continuously validated against characterization data of test structures provided by TUD.