Interdiffusion of molecular acceptors through organic layers to metal substrates mimics doping-related energy level shifts

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Erscheinungsjahr:
2009
Medientyp:
Text
Schlagworte:
  • Photoelectron spectroscopy
  • Work function
  • Level alignment
  • Organic Light Emitting Diodes (OLED)
  • Solar Cells
  • Conjugated Polymers
  • Photoelectron spectroscopy
  • Work function
  • Level alignment
  • Organic Light Emitting Diodes (OLED)
  • Solar Cells
  • Conjugated Polymers
Beschreibung:
  • Photoemission measurements reveal energy level shifts toward the Fermi level when a strong electron acceptor (tetrafluoro-tetracyanoquinodimethane, F4-TCNQ) is deposited on pristine layers of 4,4', 4 `'-tris(N,N-diphenyl-amino)triphenylamine (TDATA) or 4,4'-bis(N-carbazolyl)biphenyl (CBP). The shifts of the TDATA and CBP energy levels toward the Fermi level of the Au substrate could, in principle, arise from p-type doping of the intrinsic organic layers. While this indeed takes place in TDATA, doping of CBP by F4-TCNQ, i.e., charge transfer complex formation, does not occur. The shifts observed in CBP arise from the diffusion of F4-TCNQ toward the Au substrate, which modifies the buried metal surface potential, leading to a realignment of the energy levels of the organic overlayer. (C) 2009 American Institute of Physics. {[}DOI: 10.1063/1.3213547]
  • Photoemission measurements reveal energy level shifts toward the Fermi level when a strong electron acceptor (tetrafluoro-tetracyanoquinodimethane, F4-TCNQ) is deposited on pristine layers of 4, 4′, 4″ -tris(N,N -diphenyl-amino)triphenylamine (TDATA) or 4, 4′ -bis(N -carbazolyl)biphenyl (CBP). The shifts of the TDATA and CBP energy levels toward the Fermi level of the Au substrate could, in principle, arise from p -type doping of the intrinsic organic layers. While this indeed takes place in TDATA, doping of CBP by F4-TCNQ, i.e., charge transfer complex formation, does not occur. The shifts observed in CBP arise from the diffusion of F4-TCNQ toward the Au substrate, which modifies the buried metal surface potential, leading to a realignment of the energy levels of the organic overlayer. © 2009 American Institute of Physics.
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  • info:eu-repo/semantics/closedAccess
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Forschungsinformationssystem der UHH
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oai:www.edit.fis.uni-hamburg.de:publications/d322813f-8342-4f06-80c7-27dbbd0c85fb