A multi-scale optical model for organic light-emitting devices containing scattering layers is presented. This model describes the radiation of embedded oscillating dipoles and scattering from spherical particles. After successful model validation with experiments on a top-emitting white OLED, we show how this tool can be used for optimization with specific targets.

A multi-scale optical model for organic light-emitting devices is presented. This model describes the radiation of oscillating dipoles embedded in real OLED structures including planarization layers, color filters and scattering for enhanced light out-coupling. We show how the scattering properties impact the overall performances of white OLEDs.

We present and experimentally validate a computational model for the light propagation in thin-film solar cells that integrates non-paraxial scalar diffraction theory with non-sequential ray-tracing. The model allows computing the spectral layer absorbances of solar cells with micro-and nano-textured interfaces directly from measured surface topographies. We can thus quantify decisive quantities such as the parasitic absorption without relying on heuristic scattering intensity distributions. In particular, we find that the commonly used approximation of Lambertian scattering intensity distributions for internal light propagation is violated even for solar cells on rough textured substrates. More importantly, we demonstrate how both scattering and parasitic absorption must be controlled to maximize photocurrent.

IntroductionModeling is an essential part in research of organic light-emitting devices (OLEDs) and speeds up their development. An accurate model can be used to gain further insight into device operation and for optimizing device performance. Difficulties to simulate state-of-theart commercialized OLEDs arise from the fact that these devices are not only made of an active thin-film layer stack, but also contain thick incoherent layers such as color filters or scattering layers that enhance the light out-coupling efficiency of the device. Moreover, the area of OLED devices for lighting applications can reach several square centimeters and potential losses within electrodes cannot be neglected. For the first time, we present a comprehensive model for OLEDs spanning from microscopic charge transport and exciton dynamics to large-area panels. Our approach is able to simulate the influence of electrical conductivity enhancement in large-area electrodes and light extraction enhancement induced by incoherent scattering layers or interfaces. In a first part of this paper we repeat the fundamentals of the microscopic model, previously implemented in the commercial simulation software SETFOS [1]. In the second part we introduce the macroscopic approach for optical and electrical modeling.

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