AVS 50th International Symposium
    Organic Films and Devices Tuesday Sessions
       Session OF-TuP

Paper OF-TuP5
XPS Studies of Organic-Inorganic Interface Interaction between Conducting Polymer Chains and Si Sublayers

Tuesday, November 4, 2003, 5:30 pm, Room Hall A-C

Session: Poster Session
Presenter: S. Takemura, Kanto Gakuin University, Japan
Authors: H. Kato, Kanto Gakuin University, Japan
S. Takemura, Kanto Gakuin University, Japan
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Conducting polymer polythiophene (PT) and polypyrrole (PP) films were grown on Si substrates. PT/Si and PP/Si interfaces were fabricated by electrochemical method. Thin polymer film growth was obtained by controlling the applied voltage to the anode Si wafer in an electrochemical cell. Obtained film thickness was thin enough to be penetrated by XPS measurement to detect the organic-inorganic interface. Polymer chain configuration was also investigated by FTIR. XPS measurements were conducted closely investigating the core-level energies and spectral profiles of the atomic components. An affinity between a deposited polymer film and a Si substrate was strong compared with the case of film growth on metal oxide substrates such as ITO and SnO2. Si 2s and 2p core-level spectra which were basically composed of different Gaussian components reflect different valence states of Si interacting with upper polymer layers in comparison with the core-level spectra of non-deposited Si substrate expecting bonds between polymer chains and Si substrate layers. The lower binding energy peaks observed in Si 2p spectra of PT/Si correspond to the Si states with strong interaction between Si and PT suggesting Si-C and Si-F bonds created at the PT/Si interface. In adition to the organic-inorganic bonding, the polymer chain configuration was also investigated by FTIR. The polymer chain orientation on a Si substrate will be discussed comparing with the data obtained by RAS and ATR techniques detecting ring stretching modes of the polymer chain. The polymer chain linkage which reflects symmetric and asymmetric vibration modes will be also discussed.