@article{ScholzSauerWiessneretal.2013,
  author    = {Scholz, M. and Sauer, C. and Wiessner, M. and Nguyen, N. and Scholl, A. and Reinert, F.},
  title     = {Structure formation in organic thin films observed in real time by energy dispersive near-edge x-ray absorption fine-structure spectroscopy},
  series = {New Journal of Physics},
  volume    = {15},
  journal   = {New Journal of Physics},
  number    = {083052},
  doi       = {10.1088/1367-2630/15/8/083052},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129749},
  year      = {2013},
  abstract  = {We study the structure formation of 1,4,5,8-naphthalenetetracarboxylicacid- dianhydride (NTCDA) multilayer films on Ag(111) surfaces by energy dispersive near-edge x-ray absorption fine-structure spectroscopy (NEXAFS) and photoelectron spectroscopy. The time resolution of seconds of the method allows us to identify several sub-processes, which occur during the post-growth three-dimensional structural ordering, as well as their characteristic time scales. After deposition at low temperature the NTCDA molecules are preferentially flat lying and the films exhibit no long-range order. Upon annealing the molecules flip into an upright orientation followed by an aggregation in a transient phase which exists for several minutes. Finally, threedimensional islands are established with bulk-crystalline structure involving substantial mass transport on the surface and morphological roughening. By applying the Kolmogorov-Johnson-Mehl-Avrami model the activation energies of the temperature-driven sub-processes can be derived from the time evolution of the NEXAFS signal.},
  language  = {en}
}
@phdthesis{Foertig2013,
  author    = {F{\"o}rtig, Alexander},
  title     = {Recombination Dynamics in Organic Solar Cells},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83895},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Neben herk{\"o}mmlichen, konventionellen anorganischen Solarzellen — haupts{\"a}chlich auf Silizium basierend — ist die Organische Photovoltaik (OPV) auf dem besten Wege in naher Zukunft eine kosteng{\"u}nstige, umweltfreundliche, komplement{\"a}re Technolgie darzustellen. Die Produktionskosten, die Lebenszeit der Solarzellen sowie deren Wirkungsgrad m{\"u}ssen dabei weiter optimiert werden, um einen Markteintritt der OPV zu erm{\"o}glichen. Die vorliegende Arbeit befasst sich mit der Effizienz organischer Solarzellen und deren Limitierung durch die Rekombination von Ladungstr{\"a}gern. Um funktionsf{\"a}hige Zellen zu untersuchen, werden zeitaufgel{\"o}ste Experimente wie die Messung der transienten Photospannung (TPV), des transienten Photostroms (TPC), die Ladungsextraktion (CE) sowie die time delayed collection field (TDCF) Methode angewandt. Untersucht werden sowohl fl{\"u}ssig prozessierte als auch aufgedampfte Proben, unterschiedliche Materialzusammensetzungen und verschiedene Probengeometrien. Das Standardmaterialsystem der OPV, P3HT:PC61BM, wird bei verschiedenen emperaturen und Beleuchtungsst{\"a}rken auf die Lebenszeit und Dichte der photogenerierten Ladungstr{\"a}ger {\"u}berpr{\"u}ft. F{\"u}r den Fall spannungsunabh{\"a}ngiger Generation von Ladungstr{\"a}gern zeigt sich die Anwendbarkeit der Shockley-Gleichung auf organische Solarzellen. Des Weiteren wird ein konsistentes Modell erl{\"a}utert, welches den Idealtit{\"a}tsfaktor direkt mit der Rekombination von freien mit gefangenen, exponentiell verteilten Ladungstr{\"a}gern verkn{\"u}pft. Ein Ansatz, bekannt unter der Bezeichung j=V Rekonstruktion, erm{\"o}glicht es, den leistungslimitierenden Verlustmechanismus in unbehandelten und thermisch geheizten P3HT:PC61BM Solarzellen zu identifizieren. Dieses Verf ahren, welches TPV, CE und TDCF Messungen beinhaltet, wird auf Proben basierend auf dem neuartigen, low-band gap Polymer PTB7 in Verbindung mit dem Fulleren PC71BM ausgeweitet. W{\"a}hrend in der Zelle hergestellt aus reinem Chlorbenzol betr{\"a}chtliche geminale wie nichtgeminale Verluste zu beobachten sind, erleichtert die Zugabe eines L{\"o}sungsmittelzusatzes die Polaronenpaartrennung, was zu einer starken Reduktion geminaler Verluste f{\"u}hrt. In einer Kooperation mit dem IMEC Institut in Leuven, werden abschließend die beiden bedeutensten Probenarchitekturen organischer Solarzellen, die planare und die Misch{\"u}bergang Struktur, jeweils basierend auf CuPC und C60, bez{\"u}glich nichtgeminaler Rekombination und Ladungstr{\"a}gerverteilung miteinander verglichen. Neben den beiden experimentellen Techniken um TPV und CE werden makroskopische Simulationen herangezogen, um den Ursprung unterschiedlichen Voc vs. Lichtintensit{\"a}t-Verhaltens zu erkl{\"a}ren.},
  subject      = {Organische Solarzelle},
  language  = {en}
}
@article{OPUS4-13827,
  title     = {Search for the \(X_b\) and other hidden-beauty states in the \(π^+π^-ϒ\)(1S) channel at ATLAS},
  series = {Physics Letters B},
  volume    = {740},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2014.11.055},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-138273},
  pages     = {199-217},
  year      = {2014},
  abstract  = {This Letter presents a search for a hidden-beauty counterpart of the X(3872) in the mass ranges of 10.05-10.31 GeV and 10.40-11.00 GeV, in the channel X\(_b\)→π\(^+\)π\(^-\)ϒ(1S)(→μ\(^+\)μ\(^-\)), using 16.2 fb\(^{-1}\) of s=8 TeV \(pp\) collision data collected by the ATLAS detector at the LHC. No evidence for new narrow states is found, and upper limits are set on the product of the X\(_b\) cross section and branching fraction, relative to those of the ϒ(2S), at the 95\% confidence level using the CLSCLS approach. These limits range from 0.8\% to 4.0\%, depending on mass. For masses above 10.1 GeV, the expected upper limits from this analysis are the most restrictive to date. Searches for production of the ϒ(1\(^3\)D\(_J\)), ϒ(10860), and ϒ(11020) states also reveal no significant signals.},
  language  = {en}
}
@article{ThierschmannArnoldMittermuelleretal.2015,
  author    = {Thierschmann, H and Arnold, F and Mitterm{\"u}ller, M and Maier, L and Heyn, C and Hansen, W and Buhmann, H and Molenkamp, L W},
  title     = {Thermal gating of charge currents with Coulomb coupled quantum dots},
  series = {New Journal of Physics},
  volume    = {17},
  journal   = {New Journal of Physics},
  number    = {113003},
  doi       = {10.1088/1367-2630/17/11/113003},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-145196},
  year      = {2015},
  abstract  = {We have observed thermal gating, i.e. electrostatic gating induced by hot electrons. The effect occurs in a device consisting of two capacitively coupled quantum dots. The double dot system is coupled to a hot electron reservoir on one side (QD1), while the conductance of the second dot (QD2) is monitored. When a bias across QD2 is applied we observe a current which is strongly dependent on the temperature of the heat reservoir. This current can be either enhanced or suppressed, depending on the relative energetic alignment of the QD levels. Thus, the system can be used to control a charge current by hot electrons.},
  language  = {en}
}
@phdthesis{Fuchs2015,
  author    = {Fuchs, Franziska},
  title     = {Optical spectroscopy on silicon vacancy defects in silicon carbide},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-124071},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {This work sheds light on different aspects of the silicon vacancy in SiC: (1) Defect creation via irradiation is shown both with electrons and neutrons. Optical properties have been determined: the excitation of the vacancy is most efficient at excitation wavelengths between 720nm and 800nm. The PL decay yields a characteristic excited state lifetime of (6.3±0.6)ns. (2) Defect engineering, meaning the controlled creation of vacancies in SiC with varying neutron fluence. The defect density could be engineered over eight orders of magnitude. On the one hand, in the sample with highest emitter density, the huge PL signal could even be enhanced by factor of five via annealing mechanisms. On the other hand, in the low defect density samples, single defects with photostable room temperature NIR emission were doubtlessly proven. Their lifetime of around 7ns confirmed the value of the transient measurement. (3) Also electrical excitation of the defects has been demonstrated in a SiC LED structure. (4) The investigations revealed for the first time that silicon vacancies can even exist SiC nanocrystals down to sizes of about 60 nm. The defects in the nanocrystals show stable PL emission in the NIR and even magnetic resonance in the 600nm fraction. In conclusion, this work ascertains on the one hand basic properties of the silicon vacancy in silicon carbide. On the other hand, proof-of-principle measurements test the potential for various defect-based applications of the vacancy in SiC, and confirm the feasibility of e.g. electrically driven single photon sources or nanosensing applications in the near future.},
  subject      = {Siliciumcarbid},
  language  = {en}
}
@article{OPUS4-14339,
  title     = {Measurement of transverse energy-energy correlations in multi-jet events in pp collisions at \(\sqrt {s}\)=7 TeV using the ATLAS detector and determination of the strong coupling constant αs(m\(_{Z}\))},
  series = {Physics Letters B},
  volume    = {750},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2015.09.050},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143398},
  pages     = {427-447},
  year      = {2015},
  abstract  = {High transverse momentum jets produced in pp collisions at a centre of mass energy of 7 TeV are used to measure the transverse energy-energy correlation function and its associated azimuthal asymmetry. The data were recorded with the ATLAS detector at the LHC in the year 2011 and correspond to an integrated luminosity of 158 pb\(^{-1}\). The selection criteria demand the average transverse momentum of the two leading jets in an event to be larger than 250 GeV. The data at detector level are well described by Monte Carlo event generators. They are unfolded to the particle level and compared with theoretical calculations at next-to-leading-order accuracy. The agreement between data and theory is good and provides a precision test of perturbative Quantum Chromodynamics at large momentum transfers. From this comparison, the strong coupling constant given at the Z   boson mass is determined to be αs(m\(_{Z}\))=0.1173±0.0010 (exp.) \(^{+0.0065}_{-0.0026}\) (theo.).},
  language  = {en}
}
@article{OPUS4-14337,
  title     = {Measurement of the branching ratio Γ(Λ\(^0_b\)→ψ(2S)Λ\(^0\))/Γ(Λ\(^0_b\)→J/ψΛ\(^0\)) with the ATLAS detector},
  series = {Physics Letters B},
  volume    = {751},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2015.10.009},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143375},
  pages     = {63-80},
  year      = {2015},
  abstract  = {An observation of the View the Λ\(^0_b\)→ψ(2S)Λ\(^0\) decay and a comparison of its branching fraction with that of the Λ\(^0_b\)→J/ψΛ\(^0\) decay has been made with the ATLAS detector in proton-proton collisions at \(\sqrt {s}\)=8 TeV at the LHC using an integrated luminosity of 20.6 fb\(^{-1}\). The J/ψJ/ψ and ψ(2S) mesons are reconstructed in their decays to a muon pair, while the Λ\(^0\)→pπ\(^-\) decay is exploited for the Λ\(^0\) baryon reconstruction. The Λ\(^0_b\) baryons are reconstructed with transverse momentum p\(_T\)>10 GeV pT>10 GeV and pseudorapidity |η|<2.1. The measured branching ratio of the Λ\(^0_b\)→ψ(2S)Λ\(^0\) and Λ\(^0_b\)→J/ψΛ\(^0\) decays is Γ(Λ\(^0_b\)→ψ(2S)Λ\(^0\))/Γ(Λ\(^0_b\)→J/ψΛ\(^0\))=0.501±0.033(stat)±0.019(syst), lower than the expectation from the covariant quark model.},
  language  = {en}
}
@article{OPUS4-14423,
  title     = {Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector},
  series = {Physics Letters B},
  volume    = {749},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2015.07.079},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144231},
  pages     = {519-541},
  year      = {2015},
  abstract  = {A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb\(^{-1}\) of proton-proton collision data recorded by the ATLAS experiment at \(\sqrt {s}\)=8 TeV at the Large Hadron Collider. Five final states, targeting the decays H→WW\(^{*}\), ττ, and ZZ\(^{*}\), are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons (e or μ) without a hadronically decaying τ lepton; three light leptons; two same-charge light leptons with a hadronically decaying τ lepton; four light leptons; and one light lepton and two hadronically decaying τ leptons. No significant excess of events is observed above the background expectation. The best fit for the t\(\overline{t}\)H production cross section, assuming a Higgs boson mass of 125 GeV, is 2.1\(^{+1.4}_{-1.2}\) times the SM expectation, and the observed (expected) upper limit at the 95\% confidence level is 4.7 (2.4) times the SM rate. The p-value for compatibility with the background-only hypothesis is 1.8σ; the expectation in the presence of a Standard Model signal is 0.9σ.},
  language  = {en}
}
@article{OPUS4-14424,
  title     = {Measurement of exclusive γγ→ℓ\(^{+}\)ℓ\(^{-}\) production in proton-proton collisions at \(\sqrt {s}\)=7 TeV with the ATLAS detector},
  series = {Physics Letters B},
  volume    = {749},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2015.07.069},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144247},
  pages     = {242-261},
  year      = {2015},
  abstract  = {This Letter reports a measurement of the exclusive γγ→ℓ\(^{+}\)ℓ\(^{-}\) (ℓ=e, μℓ=e, μ) cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV by the ATLAS experiment at the LHC, based on an integrated luminosity of 4.6 fb\(^{-1}\). For the electron or muon pairs satisfying exclusive selection criteria, a fit to the dilepton acoplanarity distribution is used to extract the fiducial cross-sections. The cross-section in the electron channel is determined to be \(^{excl.}_{γγ→e^{+}e^{-}}\)=0.428 ± 0.035 (stat.) ± 0.018 (syst.) pb for a phase-space region with invariant mass of the electron pairs greater than 24 GeV, in which both electrons have transverse momentum p\(_{T}\)>12 GeV and pseudorapidity |η|<2.4. For muon pairs with invariant mass greater than 20 GeV, muon transverse momentum p\(_{T}\)>10 GeV and pseudorapidity |η|<2.4, the cross-section is determined to be \(^{excl.}_{γγ→μ^{+}μ^{-}}\) =0.628 ± 0.032 (stat.) ± 0.021 (syst.) pb. When proton absorptive effects due to the finite size of the proton are taken into account in the theory calculation, the measured cross-sections are found to be consistent with the theory prediction.},
  language  = {en}
}
@article{OPUS4-14422,
  title     = {Measurement of colour flow with the jet pull angle in t\(\overline{t}\) events using the ATLAS detector at \(\sqrt {s}\)=8 TeV},
  series = {Physics Letters B},
  volume    = {750},
  journal   = {Physics Letters B},
  organization    = {ATLAS Collaboration},
  doi       = {10.1016/j.physletb.2015.09.051},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144229},
  pages     = {475-493},
  year      = {2015},
  abstract  = {The distribution and orientation of energy inside jets is predicted to be an experimental handle on colour connections between the hard-scatter quarks and gluons initiating the jets. This Letter presents a measurement of the distribution of one such variable, the jet pull angle. The pull angle is measured for jets produced in t\(\overline{t}\) events with one W boson decaying leptonically and the other decaying to jets using 20.3 fb\(^{-1}\) of data recorded with the ATLAS detector at a centre-of-mass energy of \(\sqrt {s}\)=8 TeV at the LHC. The jet pull angle distribution is corrected for detector resolution and acceptance effects and is compared to various models.},
  language  = {en}
}