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Title: Graphene-enhanced intermolecular interaction at interface between copper- and cobalt-phthalocyanines

Interfacial electronic structures of copper-phthalocyanine (CuPc), cobalt-phthalocyanine (CoPc), and graphene were investigated experimentally by using photoelectron spectroscopy. While the CuPc/graphene interface shows flat band structure and negligible interfacial dipole indicating quite weak molecule-substrate interaction, the CuPc/CoPc/graphene interface shows a large interfacial dipole and obvious energy level bending. Controlled experiments ruled out possible influences from the change in film structure of CuPc and pure π–π interaction between CoPc and CuPc. Analysis based on X-ray photoelectron spectroscopy and density functional theory reveals that the decrease in the work function for the CuPc/CoPc/graphene system is induced by the intermolecular interaction between CuPc and CoPc which is enhanced owning to the peculiar electronic properties at the CoPc-graphene interface.
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. Department of Physics, Shaoxing University, Shaoxing 312000 (China)
  2. (COSDAF) and Department of Physics and Material Science, City University of Hong Kong, Hong Kong (China)
  3. Department of Chemistry, University of South Dakota, Vermillion, South Dakota 57069 (United States)
  4. Center of Super-Diamond and Advanced Films (COSDAF) and Department of Physics and Material Science, City University of Hong Kong, Hong Kong (China)
Publication Date:
OSTI Identifier:
22489685
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 13; Other Information: (c) 2015 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; COBALT COMPLEXES; COPPER; COPPER COMPLEXES; DENSITY FUNCTIONAL METHOD; DIPOLES; ELECTRONIC STRUCTURE; ENERGY LEVELS; FILMS; GRAPHENE; INTERACTIONS; INTERFACES; MOLECULES; PHTHALOCYANINES; SUBSTRATES; WORK FUNCTIONS; X-RAY PHOTOELECTRON SPECTROSCOPY