skip to main content

Title: Scanning tunneling microscopy/spectroscopy of picene thin films formed on Ag(111)

Using ultrahigh-vacuum low-temperature scanning tunneling microscopy and spectroscopy combined with first principles density functional theory calculations, we have investigated structural and electronic properties of pristine and potassium (K)-deposited picene thin films formed in situ on a Ag(111) substrate. At low coverages, the molecules are uniformly distributed with the long axis aligned along the [112{sup ¯}] direction of the substrate. At higher coverages, ordered structures composed of monolayer molecules are observed, one of which is a monolayer with tilted and flat-lying molecules resembling a (11{sup ¯}0) plane of the bulk crystalline picene. Between the molecules and the substrate, the van der Waals interaction is dominant with negligible hybridization between their electronic states; a conclusion that contrasts with the chemisorption exhibited by pentacene molecules on the same substrate. We also observed a monolayer picene thin film in which all molecules were standing to form an intermolecular π stacking. Two-dimensional delocalized electronic states are found on the K-deposited π stacking structure.
Authors:
; ;  [1] ;  [2] ; ; ; ;  [3] ;  [4] ;  [2] ;  [5] ;  [1] ;  [5]
  1. The Institute of Solid State Physics, The University of Tokyo, Kashiwa 277-8581 (Japan)
  2. Department of Physics, National Taiwan University, Taipei 106, Taiwan (China)
  3. Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China)
  4. Department of Physics and Earth Science Department, University of the Ryukyus, 1 Nishihara, Okinawa 903-0213 (Japan)
  5. (China)
Publication Date:
OSTI Identifier:
22308411
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CHEMISORPTION; DENSITY FUNCTIONAL METHOD; DEPOSITS; INTERACTIONS; MOLECULES; PENTACENE; POTASSIUM; SCANNING TUNNELING MICROSCOPY; SILVER 111; SPECTROSCOPY; SUBSTRATES; THIN FILMS; VAN DER WAALS FORCES