Fine structure of the electrostatic energetic disorder at the interface between disordered organic material and metal electrode

Abstract

AbstractThe physics of organic disordered materials is dominated by the effects of energetic disorder. We show that image forces reduce the electrostatic component of the total energetic disorder near an interface with a metal electrode. Typically, the standard deviation of energetic disorder is dramatically reduced at the first few layers of organic semiconductor molecules adjacent to the metal electrode and correlation properties of the disorder are different from the bulk properties. This means that the use of bulk disorder parameters (such as standard deviation of disorder) for description of the energetic disorder at the interface is poorly justified even in the case of identical spatial and chemical structure of the organic material at the interface and in the bulk of the transport layer. Implications for charge injection into organic semiconductors are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)