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.

主权项

1. A compound of general formula: wherein N is nitrogen;
X is C or N;each R is independently C1-C4 aliphatic;j is 0-3;each m is independently 0-4; andk is 0-4.