Polarization at the gold/pentacene interface

Abstract Direct and inverse photoemission spectroscopy are used to investigate the electronic polarization P = P+ + P− induced by the pentacene anion and cation at the Au/pentacene interface. Based on the spectroscopic measurements and on previously published calculations, we determine that the total polarization at the metal interface is approximately 0.67 eV larger than at the surface of the pentacene film, leading to a corresponding decrease of the interface transport gap. This reduced interface gap leads to hole and electron injection barriers of 0.47 eV and 1.17 eV, respectively.

[1]  K. Seki,et al.  ENERGY LEVEL ALIGNMENT AND INTERFACIAL ELECTRONIC STRUCTURES AT ORGANIC/METAL AND ORGANIC/ORGANIC INTERFACES , 1999 .

[2]  Antoine Kahn,et al.  Molecular level alignment at organic semiconductor-metal interfaces , 1998 .

[3]  S. Iannotta,et al.  Pentacene Thin Film Growth , 2004 .

[4]  K. Seki,et al.  Energy level alignment at organic/metal interfaces studied by UV photoemission: breakdown of traditional assumption of a common vacuum level at the interface , 1997 .

[5]  W. R. Salaneck.  Intermolecular Relaxation Energies in Anthracene , 1978 .

[6]  C. Dimitrakopoulos,et al.  Low-voltage organic transistors on plastic comprising high-dielectric constant gate insulators , 1999, Science.

[7]  Vladislav Cápek,et al.  Organic molecular crystals : interaction, localization, and transport phenomena , 1994 .

[8]  Princeton University,et al.  Dipole formation at metal/PTCDA interfaces: Role of the Charge Neutrality Level , 2004 .

[9]  David Cahen,et al.  Electron Energetics at Surfaces and Interfaces: Concepts and Experiments , 2003 .

[10]  Antoine Kahn,et al.  Charge-separation energy in films of π-conjugated organic molecules , 2000 .

[11]  Zakya H. Kafafi,et al.  Initial stages of metal/organic semiconductor interface formation , 2000 .

[12]  Z. G. Soos,et al.  Electronic polarization in pentacene crystals and thin films , 2003 .

[13]  Larry D. Boardman,et al.  High-Performance OTFTs Using Surface-Modified Alumina Dielectrics , 2003 .

[14]  Norbert Koch,et al.  Electronic structure and electrical properties of interfaces between metals and π-conjugated molecular films , 2003 .

[15]  H. Inokuchi,et al.  Reevaluation of electronic polarization energies in organic molecular crystals , 1987 .

[16]  Massimo Malagoli,et al.  The vibrational reorganization energy in pentacene: molecular influences on charge transport. , 2002, Journal of the American Chemical Society.

[17]  Norbert Koch,et al.  Conjugated organic molecules on metal versus polymer electrodes: Demonstration of a key energy level alignment mechanism , 2003 .

[18]  Ute Zschieschang,et al.  High-mobility polymer gate dielectric pentacene thin film transistors , 2002 .

[19]  Andrew G. Glen,et al.  APPL , 2001 .

[20]  C. Wöll,et al.  Importance of dewetting in organic molecular-beam deposition: Pentacene on gold , 2004 .

[21]  Marek Z. Zgierski,et al.  Theoretical calculation of the electroabsorption spectra of polyacene crystals , 1996 .

[22]  Z. G. Soos,et al.  Electronic polarization at surfaces and thin films of organic molecular crystals: PTCDA , 2002 .

[23]  H. Sirringhaus,et al.  Electron-hole interaction energy in the organic molecular semiconductor PTCDA , 1997 .

[24]  Princeton University,et al.  Barrier formation at metal-organic interfaces: dipole formation and the charge neutrality level , 2004 .

[25]  A. Kahn,et al.  Chemical and electrical properties of interfaces between magnesium and aluminum and tris-(8-hydroxy quinoline) aluminum , 2001 .