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

Abstract

We present a numerical strategy for the accurate simulation of light extraction from organic light emitting diodes (OLEDs) comprising an internal nano-particle based scattering layer. On the one hand, the light emission and propagation through the OLED thin lm system (including the scattering layer) is treated by means of rigorous wave optics calculations using the T-matrix formalism. On the other hand, the propagation through the substrate is modelled in a ray optics approach. The results from the wave optics calculations enter in terms of the initial substrate radiation pattern and the bidirectional reectivity distribution (BRDF) of the OLED stack with scattering layer. In order to correct for the truncation error due to a nite number of particles in the simulations, we extrapolate the results to innitely extended scattering layers. As an application example, we estimate the optimal particle lling fraction for an internal scattering layer in a realistic OLED geometry. The presented treatment is designed to emerge from electromagnetic theory with as few additional assumptions as possible. It could thus serve as a baseline to validate faster but approximate simulation approaches.

CELES: CUDA-accelerated simulation of electromagnetic scattering by large ensembles of spheres

“…In computer-assisted investigations of light scattering and propagation, aggregates of spheres are traditionally used to represent various types of ordered and disordered optical materials. Systems that have been modeled as multi-sphere geometries include dust [1] and soot particles [2], sand [3], white paint [4], photonic glasses [5,6], chiral structures [7], ice crystals [8], arrays of plasmonic nano-particles [9] and scattering layers in optoelectronic devices [10,11,12].…”

SMUTHI: A python package for the simulation of light scattering by multiple particles near or between planar interfaces

“…In the following subsection, we sketch the basic concepts to provide a general outline of the method. The interested reader is referred to chapters 2-3 of [28] for a more complete description of the underlying theory.…”

“…In addition to the presented use case examples, the interested reader can refer to the literature for additional applications where SMUTHI has been used during its developing stages. Published works cover various systems in physics and electrical engineering research, including the design of nanoparticle based spectrally selective reflector layers in color conversion films [53], scattering layers for light outcoupling from organic light emitting diodes [28], resonance analysis of spherical particles on a coated substrate [54], photon excitation from electron inelastic tunneling near a metallic or dielectric nano-sphere [55], the study of disordered meta surfaces [56,57] and the design of plasmonic gratings for sensing applications [58].…”

Design of Selective Reflectors Utilizing Multiple Scattering by Core–Shell Nanoparticles for Color Conversion Films

“…Light that is propagating inside the scattering sample is gradually scattered out or absorbed, leading to an extinction γ of P cyl (ρ). In analogy, we write the ansatz for the gradual out-coupling of light into one hemisphere, By considering only a finite particle ensemble of radius ρ, one underestimates the out-coupling of light to one hemisphere by P ̃ exp­(− γρ ).…”