title: Band bending in conjugated polymer layers.
abstract: We use the Kelvin probe method to study the energy-level alignment of four conjugated polymers deposited on various electrodes. Band bending is observed in all polymers when the substrate work function exceeds critical values. Through modeling, we show that the band bending is explained by charge transfer from the electrodes into a small density of states that extends several hundred meV into the band gap. The energetic spread of these states is correlated with charge-carrier mobilities, suggesting that the same states also govern charge transport in the bulk of these polymers.
authors.affiliation: Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany.
authors.forename: Ilja
authors.initials: I
authors.lastname: Lange
authors.forename: James C
authors.initials: JC
authors.lastname: Blakesley
authors.forename: Johannes
authors.initials: J
authors.lastname: Frisch
authors.forename: Antje
authors.initials: A
authors.lastname: Vollmer
authors.forename: Norbert
authors.initials: N
authors.lastname: Koch
authors.forename: Dieter
authors.initials: D
authors.lastname: Neher