Numerical analysis of nanostructures for enhanced light extraction from OLEDs

TL;DR

This paper presents a finite element method-based simulation approach for analyzing light extraction in OLEDs with nanostructures, using Floquet transform to reduce computational complexity and improve accuracy.

Contribution

It introduces a novel simulation technique combining finite element analysis with Floquet transform for efficient OLED nanostructure modeling.

Findings

Effective reduction of computational domain to a unit cell

Accurate modeling of light outcoupling with nanostructures

Enhanced understanding of geometrical optimization for OLEDs

Abstract

Nanostructures, like periodic arrays of scatters or low-index gratings, are used to improve the light outcoupling from organic light-emitting diodes (OLED). In order to optimize geometrical and material properties of such structures, simulations of the outcoupling process are very helpful. The finite element method is best suited for an accurate discretization of the geometry and the singular-like field profile within the structured layer and the emitting layer. However, a finite element simulation of the overall OLED stack is often beyond available computer resources. The main focus of this paper is the simulation of a single dipole source embedded into a twofold infinitely periodic OLED structure. To overcome the numerical burden we apply the Floquet transform, so that the computational domain reduces to the unit cell. The relevant outcoupling data are then gained by inverse Flouqet transforming. This step requires a careful numerical treatment as reported in this paper.