@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{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}
}
@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{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{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{DeviAlSutiDoscheetal.2008,
  author    = {Devi, Lekshmi Sudha and Al-Suti, Mohammed K. and Dosche, Carsten and Khan, Muhammad S. and Friend, Richard H. and K{\"o}hler, Anna},
  title     = {Triplet energy transfer in conjugated polymers : I. Experimental investigation of a weakly disordered compound},
  year      = {2008},
  abstract  = {Efficient triplet exciton emission has allowed improved operation of organic light-emitting diodes (LEDs). To enhance the device performance, it is necessary to understand what governs the motion of triplet excitons through the organic semiconductor. Here, we have investigated triplet diffusion using a model compound that has weak energetic disorder. The Dexter-type triplet energy transfer is found to be thermally activated down to a transition temperature T- T, below which the transfer rate is only weakly temperature dependent. We show that above the transition temperature, Dexter energy transfer can be described within the framework of Marcus theory. We suggest that below T-T, the nature of the transfer changes from phonon-assisted hopping to quantum-mechanical tunneling. The lower electron-phonon coupling and higher electronic coupling in the polymer compared to the monomer results in an enhanced triplet diffusion rate.},
  language  = {en}
}