Electric-field-induced conductance transition in 8-hydroxyquinoline aluminum (Alq3)

We report an electric-field-induced conductance transition from an insulating state to a conducting state in a thin layer of Alq3 sandwiched between two metal electrodes. Field-induced switching behavior with a high on-off ratio of ∼105 is observed in the devices, in which the cathode electrode is Al and the anode electrode is varied including Al, Au, and indium tin oxide. The switching behavior is absent in devices in which both electrodes have a high work function, indicating that efficient electron injection has an important role in the electric-field-induced switching behavior of Alq3-based single-layer devices.