Numerical Investigation of a 2D-Grating for Light Extraction of a Bottom Emitting OLED

Abstract

An important limiting factor for efficient white light emitting organic LEDs is the total internal reflection occurring at each interface. In a bottom emitting OLED light is trapped by reflection at the interface between the organic layers and glass substrate and at the interface between the glass substrate and air. We investigate the use of a grating at the glass substrate-air interface. In this paper we will discuss the developed 3D-simulation method and several important simulation results. Our simulation method shows that the grating extracts approximately 50% more power in comparison with a planar device. These results are comparable with the use of micro lenses.

Enhancing the Out-Coupling Efficiency of Organic Light-Emitting Diodes Using Two-Dimensional Periodic Nanostructures

“…In addition, inhomogeneous mesh was used during the simulation, the grid size was 15 nm in the x and y directions and 10 nm in the z direction. The power loss in materials (ITO and glass) during the simulation was ignored since the imaginary part of the ITO and glass index is closed to zero at the wavelength of 0.55 μm (see Figure 3) [16].…”