@article{WilsonSteffenMcKenzieetal.2002,
  author    = {Wilson, J. N. and Steffen, W. and McKenzie, T. G. and Lieser, G. and Oda, Masao and Neher, Dieter and Bunz, Uwe H. F.},
  title     = {Chiroptcial properties of poly(p-phenyleneethynylene) copolymers in thin films : large g-values},
  year      = {2002},
  language  = {en}
}
@article{OdaMeskersNothoferetal.2000,
  author    = {Oda, Masao and Meskers, S. C. J. and Nothofer, Heinz-Georg and Scherf, Ullrich and Neher, Dieter},
  title     = {Chiroptical properties of chiral-substituted polyfluorenes},
  year      = {2000},
  language  = {en}
}
@article{OdaNothoferLieseretal.2000,
  author    = {Oda, Masao and Nothofer, Heinz-Georg and Lieser, G. and Scherf, Ullrich and Meskers, S. C. J. and Neher, Dieter},
  title     = {Circularly-polarized electroluminescence from liquid-crystalline chiral polyfluorenes},
  year      = {2000},
  language  = {en}
}
@article{XuShalomPiersimonietal.2015,
  author    = {Xu, Jingsan and Shalom, Menny and Piersimoni, Fortunato and Antonietti, Markus and Neher, Dieter and Brenner, Thomas J. K.},
  title     = {Color-Tunable Photoluminescence and NIR Electroluminescence in Carbon Nitride Thin Films and Light-Emitting Diodes},
  series = {Advanced optical materials},
  volume    = {3},
  journal   = {Advanced optical materials},
  number    = {7},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2195-1071},
  doi       = {10.1002/adom.201500019},
  pages     = {913 -- 917},
  year      = {2015},
  language  = {en}
}
@article{ZenSaphiannikovaNeheretal.2005,
  author    = {Zen, Achmad and Saphiannikova, Marina and Neher, Dieter and Asawapirom, Udom and Scherf, Ullrich},
  title     = {Comparative study of the field-effect mobility of a copolymer and a binary blend based on poly(3- alkylthiophene)s},
  issn      = {0897-4756},
  year      = {2005},
  abstract  = {The performance of highly soluble regioregular poly[ (3-hexylthiophene)-co-(3-octylthiophetie)] (P3HTOT) as a semiconducting material in organic field-effect transistors (OFETs) is presented in comparison to that of the corresponding homopolymers. Transistors made from as-prepared layers of P3HTOT exhibit a mobility of ca. 7 x 10(-3) cm(2) V-1 s(-1), which is comparable to the performance of transistors made from as-prepared poly(3-hexylthiophene) (P3HT) and almost 6 times larger than the mobility of transistors prepared with poly(3-octylthiophene) (P3OT). On the other hand, the solubility parameter delta(p) of P3HTOT is close to that of the highly soluble P3OT. Moreover, compared to a physical blend of poly(3-hexylthiophene) and poly(3-octylthiophene), the mobility of P3HTOT devices is almost twice as large and the performance does not degrade upon annealing at elevated temperatures. Therefore, the copolymer approach outlined here may be one promising step toward an optimum balance between a Sufficient processability of the polymers from common organic solvents, a high solid state order, and applicable OFET performances},
  language  = {en}
}
@article{BartesaghiPerezKniepertetal.2015,
  author    = {Bartesaghi, Davide and Perez, Irene del Carmen and Kniepert, Juliane and Roland, Steffen and Turbiez, Mathieu and Neher, Dieter and Koster, L. Jan Anton},
  title     = {Competition between recombination and extraction of free charges determines the fill factor of organic solar cells},
  series = {Nature Communications},
  volume    = {6},
  journal   = {Nature Communications},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {2041-1723},
  doi       = {10.1038/ncomms8083},
  pages     = {10},
  year      = {2015},
  abstract  = {Among the parameters that characterize a solar cell and define its power-conversion efficiency, the fill factor is the least well understood, making targeted improvements difficult. Here we quantify the competition between charge extraction and recombination by using a single parameter theta, and we demonstrate that this parameter is directly related to the fill factor of many different bulk-heterojunction solar cells. Our finding is supported by experimental measurements on 15 different donor: acceptor combinations, as well as by drift-diffusion simulations of organic solar cells in which charge-carrier mobilities, recombination rate, light intensity, energy levels and active-layer thickness are all varied over wide ranges to reproduce typical experimental conditions. The results unify the fill factors of several very different donor: acceptor combinations and give insight into why fill factors change so much with thickness, light intensity and materials properties. To achieve fill factors larger than 0.8 requires further improvements in charge transport while reducing recombination.},
  language  = {en}
}
@article{PingelNeher2013,
  author    = {Pingel, P. and Neher, Dieter},
  title     = {Comprehensive picture of p-type doping of P3HT with the molecular acceptor F(4)TCNQ},
  series = {Physical review : B, Condensed matter and materials physics},
  volume    = {87},
  journal   = {Physical review : B, Condensed matter and materials physics},
  number    = {11},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {1098-0121},
  doi       = {10.1103/PhysRevB.87.115209},
  pages     = {9},
  year      = {2013},
  abstract  = {By means of optical spectroscopy, Kelvin probe, and conductivity measurements, we study the p-type doping of the donor polymer poly(3-hexylthiophene), P3HT, with the molecular acceptor tetrafluorotetracyanoquin-odimethane, F(4)TCNQ, covering a broad range of molar doping ratios from the ppm to the percent regime. Thorough quantitative analysis of the specific near-infrared absorption bands of ionized F(4)TCNQ reveals that almost every F(4)TCNQ dopant undergoes integer charge transfer with a P3HT site. However, only about 5\% of these charge carrier pairs are found to dissociate and contribute a free hole for electrical conduction. The nonlinear behavior of the conductivity on doping ratio is rationalized by a numerical mobility model that accounts for the broadening of the energetic distribution of transport sites by the Coulomb potentials of ionized F(4)TCNQ dopants. DOI: 10.1103/PhysRevB.87.115209},
  language  = {en}
}
@article{RengelGattingerSilverovaetal.1999,
  author    = {Rengel, Heiko and Gattinger, P. and Silverova, R. and Neher, Dieter},
  title     = {Conductivity measurements of electrochemically oxidized Langmuir-Blodgett films of phthalocyaninato- polysiloxanes},
  year      = {1999},
  language  = {en}
}
@article{ScharsichLohwasserSommeretal.2012,
  author    = {Scharsich, Christina and Lohwasser, Ruth H. and Sommer, Michael and Asawapirom, Udom and Scherf, Ullrich and Thelakkat, Mukundan and Neher, Dieter and Koehler, Anna},
  title     = {Control of aggregate formation in poly(3-hexylthiophene) by solvent, molecular weight, and synthetic method},
  series = {Journal of polymer science : B, Polymer physics},
  volume    = {50},
  journal   = {Journal of polymer science : B, Polymer physics},
  number    = {6},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0887-6266},
  doi       = {10.1002/polb.23022},
  pages     = {442 -- 453},
  year      = {2012},
  abstract  = {Aggregate formation in poly(3-hexylthiophene) depends on molecular weight, solvent, and synthetic method. The interplay of these parameters thus largely controls device performance. In order to obtain a quantitative understanding on how these factors control the resulting electronic properties of P3HT, we measured absorption in solution and in thin films as well as the resulting field effect mobility in transistors. By a detailed analysis of the absorption spectra, we deduce the fraction of aggregates formed, the excitonic coupling within the aggregates, and the conjugation length within the aggregates, all as a function of solvent quality for molecular weights from 5 to 19 kDa. From this, we infer in which structure the aggregated chains pack. Although the 5 kDa samples form straight chains, the 11 and 19 kDa chains are kinked or folded, with conjugation lengths that increase as the solvent quality reduces. There is a maximum fraction of aggregated chains (about 55 +/- 5\%) that can be obtained, even for poor solvent quality. We show that inducing aggregation in solution leads to control of aggregate properties in thin films. As expected, the field-effect mobility correlates with the propensity to aggregation. Correspondingly, we find that a well-defined synthetic approach, tailored to give a narrow molecular weight distribution, is needed to obtain high field effect mobilities of up to 0.01 cm2/Vs for low molecular weight samples (=11 kDa), while the influence of synthetic method is negligible for samples of higher molecular weight, if low molecular weight fractions are removed by extraction.},
  language  = {en}
}
@article{SainovaMitevaNothoferetal.2000,
  author    = {Sainova, Dessislava and Miteva, T. and Nothofer, Heinz-Georg and Scherf, Ullrich and Fujikawa, H. and Glowacki, Ireneusz and Ulanski, J. and Neher, Dieter},
  title     = {Control of color and efficiency of light-emitting diodes based on polyfluorenes blended with hole-transporting molecules},
  year      = {2000},
  language  = {en}
}