Mixed ligands 8-hydroxyquinoline aluminum complex with high electron mobility for organic light-emitting diodes

A mixed ligands 8-hydroxyquinoline complex (Alq2A) with improved electron mobility was designed for organic light-emitting diodes. The electron mobility in Alq2A was determined via transient electroluminescence (EL) from bilayer devices with structure of indium tin oxide/4,4′-bis[N-(1-naphthyl)-N-Phenyl amino]biphenyl/Alq2A∕LiF∕Al. It was found that the electron mobility in Alq2A is between (2.7and4.4)×10−6cm2∕Vs at electric fields ranging between 1.42×106 and 2.40×106V∕cm, which is higher than that in Alq3. The Alq2A also shows a higher EL efficiency in steady-state EL studies, which is considered to be derived from (1) improved electron mobility, (2) high fluorescene efficiency, and (3) good film-forming.