@article{JoshiPingelGrigorianetal.2009,
  author    = {Joshi, Siddharth and Pingel, Patrick and Grigorian, Souren and Panzner, Tobias and Pietsch, Ullrich and Neher, Dieter and Forster, Michael and Scherf, Ullrich},
  title     = {Bimodal temperature behavior of structure and mobility in high molecular weight p3ht thin films},
  issn      = {0024-9297},
  doi       = {10.1021/Ma900021w},
  year      = {2009},
  abstract  = {We report a temperature dependent crystalline structure of spin-coated thin films of high molecular weight regioregular poly(3-hexylthiophene) (P3HT) (M-n similar to 30000 g/mol) and its correlation with charge carrier mobility. These investigations show a reversible change of the crystalline structure, where the interlayer lattice spacing (100)along the alkyl side chains continuously increases up to a temperature of about 220 degrees C; in contrast, the in-plane pi-pi distance reduces with increasing temperature. These changes in structure are reversible and can be repeated several times. The temperature-induced structural properties differ for thick and thin films, pointing to a surface/interface role in stabilization of the layer morphology. In contrast to the structural changes, the carrier mobility is rather constant in the temperature range from room temperature up to 100-120 degrees C, followed by a continuous decrease. For thick layers this drop is significant and the transistor performance almost vanishes at high temperature, however, it completely recovers upon cooling back to roorn temperature. The drop of the charge carrier mobility at higher temperatures is in contrast with expectations front the structural studies, considering the increase of crystalline fraction of the polycrystalline layer. our electrical measurements Underscore that the reduction of the macroscopic mobility is mostly caused by it pronounced decrease of the intergrain transport. The thermally induced crystallization along(100) direction and the creation of numerous small crystallites at the film-substrate interface reduce the number of long polymer chain, bridging crystalline domains, which ultimately limits the macroscopic charge transport.},
  language  = {en}
}
@article{PietschPanznerLeitenbergeretal.2005,
  author    = {Pietsch, Ullrich and Panzner, Tobias and Leitenberger, Wolfram and Vartanyants, Ivan A.},
  title     = {Coherence experiments at the EDR-beamline of BESSY II},
  year      = {2005},
  language  = {en}
}
@article{PietschPanznerLeitenbergeretal.2003,
  author    = {Pietsch, Ullrich and Panzner, Tobias and Leitenberger, Wolfram and Grenzer, J{\"o}rg and Bodenthin, Th. and Geue, Thomas and M{\"o}hwald, Helmuth},
  title     = {Coherence experiments at the energy-dispersive reflectometry beamline at BESSY II},
  year      = {2003},
  language  = {en}
}
@article{PanznerGleberSantetal.2007,
  author    = {Panzner, Tobias and Gleber, Gudrun and Sant, Tushar and Leitenberger, Wolfram and Pietsch, Ullrich},
  title     = {Coherence experiments at the white-beam beamline of BESSYI},
  doi       = {10.1016/j.tsf.2006.12.002},
  year      = {2007},
  abstract  = {The third-generation X-ray source BESSYII (Berlin, Germany) provides coherent X-ray radiation which can be used for static and dynamic speckle analysis. Recently we have demonstrated that one can perform experiments with coherent white radiation provided by a bending magnet (5 < E < 20 keV). In this paper we show that the diffraction figure of the initial pinhole must be considered for the interpretation of coherent experiments. The reflectivity spectrum of a sample results from the Fresnel diffraction of the incident pinhole deformed by the static speckle features of the sample surface. For dynamical experiments all speckle like features alter with time whereas the pure Fresnel fringes remain constant. (c) 2007 Published by Elsevier B.V.},
  language  = {en}
}
@article{PietschPanznerLeitenbergeretal.2005,
  author    = {Pietsch, Ullrich and Panzner, Tobias and Leitenberger, Wolfram and Vartanyants, Ivan A.},
  title     = {Coherence experiments using white synchrotron radiation},
  year      = {2005},
  abstract  = {Experiments at the bending magnet beamline at BESSY II (EDR beamline) profit from the excellent coherence properties of third generation synchrotron sources. Considering the exponentially decaying incident spectrum, and because no optical elements are installed except slits and vacuum windows, coherence experiments can be performed between 5 keV < E < 15 keV. First, the energy dependence of spatial coherence properties were determined measuring diffraction at single and double pinholes. Next, the coherent white radiation was used to probe the morphology of thin films in reflection geometry. The recorded intensity maps (reflectivity versus sample position) provide speckle patterns which reveal the locally varying sample morphology. Setting the incident angle, alpha(i), smaller or larger than the critical angle of total external reflection, alpha(c), one should be able to separate the surface height profile from the subsurface density modulation of a sample. The validity of this approach is verified at the example of reciprocal space maps taken from a polymer surface where we could reconstruct the lateral height profile from speckle data. (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}
@article{PietschLeitenbergerWendrocketal.2003,
  author    = {Pietsch, Ullrich and Leitenberger, Wolfram and Wendrock, Horst and Bischoff, Lothar and Panzner, Tobias and Grenzer, J{\"o}rg and Pucher, Andreas},
  title     = {Double pinhole diffraction of white synchrotron radiation},
  year      = {2003},
  language  = {en}
}
@article{SendvonKozierowskiPanzneretal.2009,
  author    = {Send, Sebastian and von Kozierowski, Marc and Panzner, Tobias and Gorfman, Semen and Nurdan, Kivanc and Walenta, Albert H. and Pietsch, Ullrich and Leitenberger, Wolfram and Hartmann, Robert and Str{\"u}der, Lothar},
  title     = {Energy-dispersive Laue diffraction by means of a frame-store pnCCD},
  issn      = {0021-8898},
  doi       = {10.1107/S0021889809039867},
  year      = {2009},
  language  = {en}
}
@article{HennebergRochonPanzneretal.2004,
  author    = {Henneberg, Oliver and Rochon, Paul and Panzner, Tobias and Finkelstein, Kenneth D. and Geue, Thomas and Saphiannikova, Marina and Pietsch, Ullrich},
  title     = {In-situ Investigation of Surface Relief Grating Formation in Photosensitive Polymers},
  year      = {2004},
  language  = {en}
}
@article{HennebergPietschPanzneretal.2006,
  author    = {Henneberg, Oliver and Pietsch, Ullrich and Panzner, Tobias and Geue, Thomas and Finkelstein, Kenneth D.},
  title     = {Simultaneous X-ray and visible light diffraction for the investigation of surface relief and density grating formation in azobenzene containing polymer films},
  issn      = {1542-1406},
  doi       = {10.1080/15421400500383345},
  year      = {2006},
  abstract  = {The development of surface relief and density patterns in azobenzene polymer films was studied by diffraction at two different wavelengths. We used x-ray diffraction of synchrotron radiation at 0.124 nm in combination with visible light diffraction at a wavelength of 633 nm. In contrast to visible light scattering x-ray diffraction allows the separation of a surface relief and a density grating contribution due to the different functional dependence of the scattering power. Additionally, the x-ray probe is most sensitive for the onset of the surface grating formation},
  language  = {en}
}
@article{PietschPanznerPfeifferetal.2005,
  author    = {Pietsch, Ullrich and Panzner, Tobias and Pfeiffer, Franz and Robinson, Ian K.},
  title     = {Substrate morphology repetition in "thick" polymer films},
  year      = {2005},
  abstract  = {Using Grazing-incidence small-angle scattering (GISAXS) technique we investigated the surface morphology of polymer films spin-coated on different silicon substrates. As substrates we used either technologically smooth silicon wafers or the same silicon wafer coated with thin aluminium or gold films which show a granular structure at the surface. Although the polymer thickness exceeds 300 nm the GISAXS pattern of the film shows the same in-plane angle distribution Delta2theta as the underlying substrate. Annealing the polymer films at a temperature above its glass transition temperature Delta2theta changed from a broad to a narrow distribution as it is typically for films on pure silicon. The experiment can be interpreted by roughness replication and density fluctuation within the polymer film created while spin-coating at room temperature. Due to the low segment mobility there are density fluctuations which repeat the surface morphology of the substrate. Above the glass temperature the polymer density can be homogenized independently from the morphology of the substrate. (C) 2004 Elsevier B.V. All rights reserved},
  language  = {en}
}