Small Molecular Materials for Phosphorescent Organic Light-Emitting Diodes

Abstract

Organic light-emitting diodes (OLEDs) using phosphorescent dyes as emitting materials are expected to be applied to efficient full-color flat-panel displays and efficient solid state lightings because their emission efficiencies are much higher than those of conventional fluorescent OLEDs. Extensive research and development efforts have been devoted to OLEDs using phosphorescent materials ever since bright emission was obtained from an OLED using a porphyrin derivative in 1998 and from an OLED using an iridium complex in 1999. There are lots of reports on the development of phosphorescent materials which emit blue, green, or red and the performance of OLEDs using these materials. In this article, we review the research and development of the phosphorescent materials for the OLEDs.