Host Materials for Single-Layer Phosphorescent OLEDs

摘要

New carbazole-based compounds are provided that are useful as host materials for singlelayer and multilayer organic light-emitting diode (OLED) devices. Highly efficient single-layer OLEDs have been demonstrated using new N-heterocyclic carbazole-based host materials. Phosphorescent OLEDs with a structure of ITO/MoO₃/host/host:dopant/host/Cs₂CO₃/Al have been fabricated in which the new host materials act simultaneously as electron-transport, holetransport and host layer. Using this design, devices with maximum current and external quantum efficiencies of 92.2 cd and 26.8% were achieved, the highest reported to date for a single-layer OLED.