Highly efficient electron injection and transport materials

摘要

The charge balance in OLEDs is essential for achieving high device performance. As holes are the majority carrier in common OLEDs, highly efficient electron injection materials (EIMs) and electron transporting materials (ETMs) are highly desired. In our work, it is discovered that some of the alkali compounds, such as alkali carbonates and nitrides, would decompose to form alkali metal during vacuum thermal evaporation. These materials can be used as EIM to improve OLED performances. We have also found bipolar transporting materials are ideal for ETM in OLEDs. For an example, a pyridine-containing anthracene derivative developed in our lab show high electron and hole mobilities of around 10-3 cm2 V-l s-1. Furthermore, cyclic voltammetry measurements find that both the cations and anions of the new material are stable, which may improve the stability of OLEDs.