More light from organic light-emitting diodes

Device efficiency of organic light‐emitting diodes: Progress by improved light outcoupling

“…Note that these simulations were performed at a single wavelength of 600 nm and a semi‐infinite glass substrate was assumed to avoid back reflected light from the glass–air interface appearing as top emission (see also Refs. 99, 102).…”

Luminescent Neutral Platinum Complexes Bearing an Asymmetric N^N^N Ligand for High‐Performance Solution‐Processed OLEDs

“…In the past few decades, the search for highly emitting materials for electroluminescent devices has attracted a great deal of attention because of their potential applications in energy‐saving organic light‐emitting diodes (OLEDs) for full‐color displays and solid‐state lighting 1. Phosphorescent transition metal complexes are particularly appropriate for this purpose due to the strong spin‐orbit coupling exerted by the heavy metal 2.…”

A look inside white OLEDs

“…The OLED functions as an optical microcavity, in which exciton formation close to metallic electrodes must be avoided because this would lead to non-radiative decay. By carefully tuning the thicknesses of all layers, the outcoupling efficiency can be optimized [3]. A special role is again played by the interlayer between the green and blue layer.…”

“…If it is known where in the OLED the emission takes place, the external emission can be readily calculated by optical microcavity modelling, using the known dielectric properties of all layers in the stack and representing a radiatively decaying exciton as a classical dipole antenna [3]. The total outcoupled radiation of the OLED is the sum of the outcoupled radiation of all dipoles in the stack.…”

“…It is important that a large fraction of the light actually leaves the structure and can be used for illumination. An excellent review of the efficiency of the light outcoupling from OLEDs was given two years ago in this journal by Brütting et al [3]. Here, we focus on the light generation, and in particular on the question where in these structures emission of the different colours takes place.…”