title: Dispersive electron transport in tris(8-hydroxyquinoline) aluminum (Alq3) probed by impedance spectroscopy.
abstract: Electron transport in tris(8-hydroxyquinoline) aluminum (Alq3) is investigated by impedance spectroscopy under conditions of space-charge limited conduction (SCLC). Existing SCLC models are extended to include the field dependence of the charge carrier mobility and energetically distributed trap states. The dispersive nature of electron transport is revealed by a frequency-dependent mobility with a dispersion parameter alpha in the range 0.4-0.5, independent of temperature. This indicates that positional rather than energetic disorder is the dominant mechanism for the dispersive transport of electrons in Alq3.
authors.affiliation: Experimental Physics II, University of Bayreuth, 95440 Bayreuth, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Berleb
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Brütting