@article{SmertenkoDimitrievSchraderetal.2004,
  author    = {Smertenko, P. S. and Dimitriev, O. P. and Schrader, Sigurd and Brehmer, Ludwig},
  title     = {Doping of polyaniline by transition metal salts : current-voltage characteristics of the ITO/polymer film/metal heterostructures},
  issn      = {0379-6779},
  year      = {2004},
  abstract  = {Films of emeraldine base of polyaniline (PAni) doped by various transition metal salts have been prepared, and current-voltage characteristics of the indium-tin oxide (ITO)/PAni film/metal electrode heterostructures were investigated. It was found that the electrical characteristics of the heterostructures are greatly affected by the dopant used and the metal electrode used. Different dopants resulted in different current anomalies with asymmetric current-voltage characteristics. Depending on the dopant used, the exponential and power law of the current behavior can be distinguished. Depending on the metal electrode used, two different regimes of current passing have been found at low applied voltages, namely, a nearly ohmic regime for the indium electrode, and a diode regime for the aluminum electrode. The diode regime was found to accompany by a positive charge accumulation in the film near the film/metal interface, which creates a built-in potential in the film. The amount of positive charges accumulated at the interface and therefore the value of the built-in potential can be reversibly increased or reduced by successive runs of the applied voltage in the forward or reverse direction, respectively. (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{SchraderPenzkoferHolzeretal.2004,
  author    = {Schrader, Sigurd and Penzkofer, Alfons and Holzer, W. and Velagapudi, Ramakrishna and Grimm, Bernhard},
  title     = {Laser spectroscopic investigation of a new precursor - type polyparaphenylenevinylene},
  issn      = {0022-2313},
  year      = {2004},
  abstract  = {Optical, structural and morphological properties of thin films of polyparaphenylenevinylene (PPV) formed by an alkyl sulfinyl precursor route have been studied. Thin films were fabricated on an optical glass and on quartz glass either by spin-coating of the precursor solution or by layer-by-layer deposition using Langmuir-Blodgett technique. PPV precursor films were also spin-coated on gold-coated glass in order to study thin-film optical parameters by surface plasmon spectroscopy. We have been successful in forming about 40 precursor mono layers on quartz glass by Langmuir- Blodgett technique using optimized surface pressure and dipping conditions. After thermal conversion of the precursor layers good quality fluorescent PPV films of yellow colour have been obtained. Optical characterization of the films was carried out by linear absorption and emission spectroscopy, ellipsometry, and surface plasmon spectroscopy. Structural and morphological studies on the thin films were carried out by using X-ray scattering and atomic force microscopy. Wave- guided travelling-wave laser action has been achieved in a PPV film on quartz glass. The sample was transversally pumped with picosecond laser pulses (wavelength 347.15 nm, duration 35 ps). Laser emission occurred at 550 nm for pump pulse energy densities above 1 x 10(-4) J cm(-2). (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{NagyStrahlNeuhauseretal.2004,
  author    = {Nagy, A. and Strahl, A. and Neuhauser, H. and Schrader, Sigurd and Behrens, I. and Peiner, E. and Schlachetzki, A.},
  title     = {Mechanical spectroscopy of thin layers of PPV polymer on Si substrates},
  issn      = {0921-5093},
  year      = {2004},
  abstract  = {The vibrating reed technique with electro "static" excitation and optical detection has been applied to investigate thin layers of poly-phenylene-vinylene, deposited by spin coating onto microfabricated Si cantilevers, during temperature cycling programs between 90 and 540 K at a rate of 1 K/min. From the vibration frequencies the Young's modulus of the film can be estimated to be about 10 MPa at room temperature in the precursor phase (if prepared from a solution in toluene), which increases by conversion to the conjugate bonded polymer to about 50 MPa. The temperature dependence of internal friction reveals the processes of gamma relaxations (crankshaft motion of side branches in the precursor) and P-relaxation (movements of a few monomer blocks in the polymer chain), as well as peaks indicating the structural transformations during conversion, and possibly a glass transition in the amorphous precursor phase. After conversion only the P-relaxation persists. (C) 2003 Elsevier B.V. All rights reserved},
  language  = {en}
}