@article{ZhangHayerAlSutietal.2006,
  author    = {Zhang, Ning and Hayer, Anna and Al-Suti, Mohammed K. and Al-Belushi, Rayya A. and Khan, Muhammad S. and K{\"o}hler, Anna},
  title     = {The effect of delocalization on the exchange energy in meta- and para-linked Pt-containing carbazole polymers and monomers},
  doi       = {10.1063/1.2200351},
  year      = {2006},
  abstract  = {A series of novel platinum-containing carbazole monomers and polymers was synthesized and fully characterized by UV-VIS absorption, luminescence, and photoinduced absorption studies. In these compounds, a carbazole unit is incorporated into the main chain via either a para- or a meta-linkage. We discuss the effects of linkage and polymerization on the energy levels of S-1, T-1, and T-n. The S-1-T-1 splitting observed for the meta-linked monomer (0.4 eV) is only half of that in the para-linked monomer (0.8 eV). Upon polymerization, the exchange energy in the para- linked compound reduces, yet still remains larger than in the meta-linked polymer. We attribute the difference in exchange energy to the difference in wave function overlap between electron and hole in these compounds. (c) 2006 American Institute of Physics},
  language  = {en}
}
@article{YangVardenyKoehleretal.2004,
  author    = {Yang, C. and Vardeny, Z. V. and K{\"o}hler, Anna and Wohlgenannt, M. and Al-Suti, Mohammed K. and Khan, Muhammad S.},
  title     = {Spectroscopic study of spin-dependent exciton formation rates in pi-conjugated semiconductors : Comparison with electroluminescence techniques},
  year      = {2004},
  abstract  = {It has been found in recent measurements that the singlet-to-triplet exciton ratio in organic light-emitting diodes (OLEDs) is larger than expected from spin degeneracy, and that singlet excitons form at a larger rate than triplets. We employed the technique of optically detected magnetic resonance to measure the spin-dependent exciton formation rates in films of a polymer and corresponding monomer, and explore the relation between the formation rates and the actual singlet-to-triplet ratio measured previously in OLEDs. We found that the spin-dependent exciton formation rates can indeed quantitatively explain the observed exciton yields, and that singlet formation rates and yields are significantly enhanced only in polymer OLEDs, but not in OLEDs made from the corresponding monomer},
  language  = {en}
}
@article{SandeeWilliamsEvansetal.2004,
  author    = {Sandee, A. J. and Williams, Charlotte K. and Evans, N. R. and Davies, J. E. and Boothby, C. E. and K{\"o}hler, Anna and Friend, Richard H. and Holmes, Andrew B.},
  title     = {Solution-processible conjugated electrophosphorescent polymers},
  year      = {2004},
  language  = {en}
}
@article{ParkinsonAharonChangetal.2007,
  author    = {Parkinson, P. and Aharon, E. and Chang, M. H. and Dosche, Carsten and Frey, G. L. and K{\"o}hler, Anna and Herz, L. M.},
  title     = {Dimensionality-dependent energy transfer in polymer-intercalated SnS2 nanocomposites},
  doi       = {10.1103/Physrevb.75.165206},
  year      = {2007},
  abstract  = {We have investigated the influence of dimensionality on the excitation-transfer dynamics in a conjugated polymer blend. Using time-resolved photoluminescence spectroscopy, we have measured the transfer transients for both a three-dimensional blend film and for quasi-two-dimensional monolayers formed through intercalation of the polymer blend between the crystal planes of an inorganic SnS2 matrix. We compare the experimental data with a simple, dimensionality- dependent model based on electronic coupling between electronic transition moments taken to be point dipoles. Within this approximation, the energy-transfer dynamics is found to adopt a three-dimensional character in the solid film and a two-dimensional nature in the monolayers present in the SnS2-polymer nanocomposite.},
  language  = {en}
}
@article{MermerVeeraraghavanFrancisetal.2005,
  author    = {Mermer, {\"O}. and Veeraraghavan, G. and Francis, T. L. and Sheng, Y. and Nguyen, D. T. and Wohlgenannt, M. and K{\"o}hler, Anna and Al-Suti, Mohammed K.},
  title     = {Large magnetoresistance in nonmagnetic pi-conjugated semiconductor thin film devices},
  year      = {2005},
  abstract  = {Following the recent observation of large magnetoresistance at room temperature in polyfluorene sandwich devices, we have performed a comprehensive magnetoresistance study on a set of organic semiconductor sandwich devices made from different pi-conjugated polymers and small molecules. The study includes a range of materials that show greatly different chemical structure, mobility, and spin-orbit coupling strength. We study both hole and electron transporters at temperatures ranging from 10 K to 300 K. We observe large negative or positive magnetoresistance (up to 10\% at 300 K and 10 mT) depending on material and device operating conditions. We discuss our results in the framework of known magnetoresistance mechanisms and find that none of the existing models can explain our results.},
  language  = {en}
}
@article{MakHayerPascuetal.2005,
  author    = {Mak, Chris S. K. and Hayer, Anna and Pascu, S. I. and Watkins, Scott E. and Holmes, Andrew B. and K{\"o}hler, Anna and Friend, Richard H.},
  title     = {Blue-to-green electrophosphorescence of iridium-based cyclometallated materials.},
  issn      = {0022-4936},
  doi       = {10.1039/b508695gb70},
  year      = {2005},
  language  = {en}
}
@article{KoehlerBeljonne2004,
  author    = {K{\"o}hler, Anna and Beljonne, David},
  title     = {The singlet-triplet exchange energy in conjugated polymers},
  issn      = {1616-3028},
  year      = {2004},
  language  = {en}
}
@article{KhanAlMandharyAlSutietal.2004,
  author    = {Khan, Muhammad S. and Al-Mandhary, Muna R. A. and Al-Suti, Mohammed K. and Al-Battashi, Fathiya R. and Al-Saadi, Sultan and Bjernemose, Jens K. and Mahon, Mary F. and Chawdhury, Nazia and Yonus, Muhammad and K{\"o}hler, Anna and Teat, Simon J. and Marseglia, Elizabeth A. and Tedesco, Emilio and Feeder, Neil and Ahrens, Birte and Raithby, Paul R.},
  title     = {Synthesis, characterisation and optical spectroscopy of platinum(II) di-ynes and poly-ynes incorporating condensed aromatic spacers in the backbone},
  issn      = {1477-9226},
  doi       = {10.1039/B405070C},
  year      = {2004},
  language  = {en}
}
@article{KhanSreearunothaiHerzetal.2004,
  author    = {Khan, Amena L. T. and Sreearunothai, Paiboon and Herz, Laura M. and Banach, Michael J. and K{\"o}hler, Anna},
  title     = {Morphology-dependent energy transfer within polyfluorene thin films},
  year      = {2004},
  language  = {en}
}
@article{HayerKoehlerArisietal.2004,
  author    = {Hayer, Anna and K{\"o}hler, Anna and Arisi, E. and Bergenti, I. and Dediu, A. and Taliani, C. and Al-Suti, Mohammed K. and Khan, Muhammad S.},
  title     = {Polymer light-emitting diodes with spin-polarised charge injection.},
  issn      = {0379-6779},
  year      = {2004},
  language  = {en}
}