Spirobifluorene-2,7-dicarbazole-4′-phosphine Oxide as Host for High-Performance Single-Layer Green Phosphorescent OLED Devices

Abstract

A new host material based on the 2,7,4'-substituted spirobifluorene platform has been designed and used in single-layer phosphorescent OLED with very high efficiency (EQE = 13.2%) and low turn-on voltage (2.4 V). This performance is among the best reported for green single-layer PhOLEDs and may open new avenues in the design of host materials for single-layer devices.