Affiliation:
1. Merck Electronics KGaA, Frankfurter Str. 250 Darmstadt Germany 64293
Abstract
In this article, we review recent developments of modern host
materials for green phosphorescent OLEDs. We show that optical
emitter orientation can be enhanced significantly by tailored
hosts, resulting in an increased device efficiency. Beyond
efficiency, matching the host system to the applied emitter is
shown to be key for an optimum device performance. In addition
to maximized classical device performance parameters, modern
hosts need to fulfill further requirements. Prominent examples
are the tuning of the OLED stack capacitance by the host or the
development of stable premixed host systems, enabling the
evaporation of multiple host materials from one crucible.