The mechanism of Schottky-barrier formation in polyacetylene

Abstract
An investigation of metal‐polyacetylene contacts by using x‐ray photoemission spectroscopy is reported. For undoped p‐type polyacetylene, Mgmetal formed a rectifying contact with a Schottky‐barrier height of ≳0.6 eV; Aumetal formed a pure ohmic contact. Changes in band bending in the polyacetylene with metal deposition were directly observed by x‐ray photoemission spectroscopy and correlated with I‐V transport measurements. Our results indicate that the mechanism for Schottky‐barrier formation in polyacetylene is the electrostatic match of work functions at the metal‐polyacetylene interface and that there are no intrinsic or extrinsic filled interface states within the polyacetylene band gap.