Unicolored phosphor-sensitized fluorescence for efficient and stable blue OLEDs

• Published in: Nature communications 2018-11, Vol.9 (1), p.4990-8, Article 4990
• Main Authors: Heimel, Paul, Mondal, Anirban, May, Falk, Kowalsky, Wolfgang, Lennartz, Christian, Andrienko, Denis, Lovrincic, Robert
• Format: Article
• Language: English
• Subjects: 119/118; 140/125; 639/301/1019/1020/1091; 639/301/1034/1035; Decay; Emitters; Fluorescence; Humanities and Social Sciences; Light emitting diodes; multidisciplinary; Organic light emitting diodes; Phosphorescence; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-07432-2

Improving lifetimes and efficiencies of blue organic light-emitting diodes is clearly a scientific challenge. Towards solving this challenge, we propose a unicolored phosphor-sensitized fluorescence approach, with phosphorescent and fluorescent emitters tailored to preserve the initial color of phosphorescence. Using this approach, we design an efficient sky-blue light-emitting diode with radiative decay times in the submicrosecond regime. By changing the concentration of fluorescent emitter, we show that the lifetime is proportional to the reduction of the radiative decay time and tune the operational stability to lifetimes of up to 320 h (80% decay, initial luminance of 1000 cd/m 2 ). Unicolored phosphor-sensitized fluorescence provides a clear path towards efficient and stable blue light-emitting diodes, helping to overcome the limitations of thermally activated delayed fluorescence. The potential of organic light-emitting diodes (OLEDs) for solid-state lighting applications is limited by the need to develop efficient blue emitters. Here, the authors utilize a unicolored phosphor-sensitized fluorescence strategy to demonstrate efficient sky-blue OLEDs with enhanced lifetime.