38.3: Simulations, Measurements, and Optimization of OLEDs with Scattering Layer

Abstract

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.

Accurate optical simulation of nano-particle based internal scattering layers for light outcoupling from organic light emitting diodes

“…The scattering layer is then treated as an incoherent layer in a net radiation algorithm considering the propagation through a stack of multiple coherent and incoherent layers. A good concordance between simulation and experimental results was observed [10]. The obvious question is if for the propagation through the scattering layer a ray optics treatment is justied or if wave optics calculations are necessary.…”

“…Inside the substrate, the propagation of light can be modelled by a net distribution of power over the propagation angles and polarizations. The treatment is similar to the one presented in [10]. To achieve a discrete notation for the radiation distributions, we introduce a regular grid of N α + 1 polar angles between 0 and π/2:…”

“…< ρ Nsim . Then, we use expression (10) to extrapolate the initial substrate power resulting from these simulations to ρ = ∞. For the angle dependent extrapolated initial extraction pattern, we can then estimate In other words, the extrapolation is done only for the integrated power ux into the substrate, whereas the angular distribution is taken from the simulation result for the maximal number of particles, which is then scaled to the extrapolated power ux.…”

“…One reason is the broad range of the involved length scales, that reach from the particle diameters and layer thicknesses in the nanometer scale, over the decay length of the waveguide modes that is typically in the micron scale to the substrate thickness in the millimeter scale. Previous studies have either assumed a microscopic approach [7,9] or employed a ray optics model for the scattering layer [10]. In either case, certain assumptions have to be made on the microscopic or the macroscopic aspects of light propagation.…”

37.4: Light conversion and scattering properties of QD films for display applications: Angle‐resolved optical spectroscopy and numerical simulation

“…In the following we use our experimental results to qualitatively validate the down-conversion model embedded in our commercial OLED/OPV simulation software Setfos. [5] In addition to the electro-optical simulation of complex thin film devices [6][7][8], the tool offers a 2D ray-tracing engine to model scattering, absorption and re-emission by nanoparticles in a QD film. Given a set of parameters describing the QD film, the software computes the absorption and transmission properties as a function of the angle.…”