White organic light-emitting diodes: Status and perspective

TL;DR

This review discusses the development, physics, and light outcoupling strategies of white OLEDs, highlighting their potential as next-generation, efficient, and color-tunable light sources based on organic materials.

Contribution

It provides a comprehensive overview of device concepts and light outcoupling techniques for white OLEDs, emphasizing recent advancements and future perspectives.

Findings

High efficiency and color-tunability of white OLEDs

Significant photon trapping within thin-film structures

Promising light outcoupling strategies identified

Abstract

White organic light-emitting diodes (OLEDs) are ultra-thin, large-area light sources made from organic semiconductor materials. Over the last decades, much research has been spent on finding the suitable materials to realize highly efficient monochrome and white OLEDs. With their high efficiency, color-tunability, and color-quality, white OLEDs are emerging to become one of the next generation light sources. In this review, we discuss the physics of a variety of device concepts that are introduced to realize white OLEDs based on both polymer and small molecule organic materi als. Owing to the fact that about 80 % of the internally generated photons are trapped within the thin-film layer structure, we put a second focus on reviewing promising concepts for improved light outcoupling.