Theoretical reconstruction and elementwise analysis of photoelectron spectra for imidazolium-based ionic liquids M. Reinmöller, A. Ulbrich, T. Ikari, J. Preiß, O. Höfft, F. Endres, S. Krischok, W. J. D. Beenken,Phys. Chem. Chem. Phys. 2011, DOI: 10.1039/C1CP22152C

Subbandgap absorption in polymer-fullerene solar cells, M. Presselt, M. Bärenklau, R. Rösch, W. J. D. Beenken, E. Runge, S. Shokhovets, H. Hoppe, G. Gobsch, Appl. Phys. Lett. 97, 253302 (2010)

Surface electronic structure of imidazolium-based ionic liquids studied by electron spectroscopy, T. Ikari, A. Keppler, M. Reinmöller, W. J. D. Beenken, S. Krischok, M. Marschewski, W. Maus-Friedrichs, O. Höfft, F. Endres, <//em></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//></><//>e-J, Surf. Sci. Nanotech. 8, 241 (2010)

Excitons in Conjugated polymers: Do we need a Paradigma change?, W. J. D. Beenken, Phys. Stat. Sol. A 206, 2750 (2009)

Photoinduced Charge Transfer in Fullerene-Oligothiophene Dyads - A Quantum-Chemical Study, W. J. D. Beenken, Chem. Phys. 357, 144 (2009)

Excited state properties of neutral and charged terfluorene with and without and keto-defect , W. J. D. Beenken, M. Sun, G. Zhao, T. Pullerits, Phys. Stat. Sol. B 245, 849 (2008)

Torsional Potentials for the Ground and Excited State of Bithiophene Calculated by Time-dependent Density Functional Theory, W. J. D. Beenken, Chem. Phys. 349, 250 (2008)

Temperature-Dependent Electronic and Vibrational Structure of the 1-Ethyl-3-methylimidazolium Bis(trifluoromethylsulfonyl)amide Room-Temperature Ionic Liquid Surface: A Study with XPS, UPS, MIES, and HREELS, S. Krischok, M. Eremtchenko, M. Himmerlich, P. Lorenz, J. Uhlig, A. Neumann, R. Öttking, W. J. D. Beenken, O. Höfft, S. Bahr, V. Kempter, J. A. Schaefer, J. Phys. Chem. B 111, 4801 (2007)

A comparative study on the electronic structure of the 1-Ethyl-3-methylimidazolium bis(trifluorosulfonyl)amide RT-ionic liquid by electron spectroscopy and first principles calculations, S. Krischok, R. Öttking, W.J.D. Beenken, M. Himmerlich, P. Lorenz, O. Höfft, S. Bahr, V. Kempter, J.A. Schaefer, Z. Phys. Chem. 220, 1407 (2006)

Conformational disorder of conjugated polymers, S. Westenhoff, W. J. D. Beenken, A. Yartsev, N. C. Greenham, J. Chem. Phys. 125, 154903 (2006)

Anomalous energy transfer dynamics due to torsional relaxation in a polythiophene, S. Westenhoff, W. J. D. Beenken, R. H. Friend, N. C. Greenham, A. Yartsev, V. Sundström, Phys. Rev. Lett. 97, 166804 (2006)

Control of Emission by Intermolecular Fluorescence Resonance Energy Transfer and Intermolecular Charge Transfer, M. Sun, W. J. D. Beenken, P. Kjellberg, T. Pullerits, and K. Han, J. Phys. Chem. A 110, 6324 (2006)

Comparison of the electronic structure of PPV and its derivative DIOXA-PPV, M. Sun, P. Kjellberg, W. J. D. Beenken, and T. Pullerits, Chem. Phys. 327, 474 (2006)

Spectral Broadening and Diffusion by Torsional Motion in Biphenyl , W. J. D. Beenken and H. Lischka, J. Chem. Phys. 123, 144311 (2005)

The electronic states of polyfluorene co-polymers with alternating donor-acceptor units, K. G. Jespersen, W. J. D. Beenken, Y. Zaushitsyn, A. Yartsev, M. Andersson, T. Pullerits, and V. Sundström, J. Chem. Phys.121, 12613 (2004)

Spectroscopic units in conjugated polymers: A quantum-chemically founded concept? W. J. D. Beenken and T. Pullerits, J. Phys. Chem. B 108, 6164 (2004)

Self-assembly of the light harvesting pigment-protein LH2 revealed by ultrafast spectroscopy and electron microscopy, A. Schubert, A. Stenstam, W. J. D. Beenken, J. L. Herek, R. J. Cogdell, T. Pullerits, and V. Sundström, Biophys. J. 86, 2363 (2004)

Excitonic coupling in polythiophenes: Comparison of different calculation methods, W. J. D. Beenken and T. Pullerits, J. Chem. Phys. 120, 2490 (2004)

Theory of Nonlinear Polarization Spectroscopy in the Frequency Domain (NLPF) with Applications to Photosynthetic Antennae, W. J. D. Beenken,
PhD-Thesis, Humboldt University Berlin, Germany, 2003 (PDF-file ~12MB) 

Potential surfaces and delocalization of excitons in dimers, W. J. D. Beenken, M. Dahlbom, P. Kjellberg, and T. Pullerits, J. Chem. Phys. 117, 5810 (2002)

Collective excitation dynamics and polaron formation in molecular aggregates, M. Dahlbom, W. Beenken, V. Sundström, and T. Pullerits, Chem. Phys. Lett. 364, 556 (2002)

Spectral Substructure and Excitonic Interactions in the Minor Photosystem II Antenna Complex CP29 as Revealed by Non-Linear Polarization Spectroscopy in the Frequency Domain, B.  Voigt, K.-D. Irrgang, J. Ehlert, W. Beenken, G. Renger, D. Leupold, H. Lokstein, Biochem. 41, 3049 (2002)

Excitonic Coupling of Chlorophylls in the Plant Light-Harvesting Complex LHC-II, A. Schubert, W. J. D. Beenken, H. Stiel, B. Voigt, J. Ehlert, H. Lokstein, D. Leupold, Biophys. J. 82, 1030 (2002)

Collective excitation dynamics in molecular aggregates: Exciton relaxation, self-trapping and polaron formation , M. Dahlbom, W. Beenken, V. Sundström, and T. Pullerits, in Biophysical Chemistry: Membranes and Proteins, eds. R. H. Templer and R. Leatherbarrow, Royal Society of Chemistry, London, 2001,  pp. 118-135

Spectral substructure and excitonic interactions in the plant antenna complexes LHC II and CP29 as revealed by non-linear laser spectroscopy , H. Lokstein, B. Voigt, A. Schubert, M. Krikunova, W. Beenken, K. Teuchner, J. Ehlert, K.-D. Irrgang, G. Renger, D. Leupold, in Proceedings of the 12th International Congress on Photosynthesis, Brisbane, Australia (2001)

Pigment-protein architecture in the light harvesting antenna complexes of purple bacteria: Does the crystal structure reflect the native pigment-protein arrangement? D. Leupold, B. Voigt, W. Beenken, H. Stiel, FEBS Letters 480, 73 (2000)

A new set-up for nonlinear polarization spectroscopy in the frequency domain: Experimental examples and theoretical background, B. Voigt, F. R. Nowak, W. Beenken, Meas. Sci. Technol. 10, N7 (1999)

Subband analysis of molecular electronic transitions by nonlinear polarization spectroscopy in the frequency domain, W. Beenken, J. Ehlert, J. Chem. Phys. 109, 10126 (1998)

Direct observation of spectral substructure in the Qy-absorption band of light harvesting complex II by nonlinear polarisation spectroscopy in the frequency domain at low temperature, A. Schubert, B. Voigt, F. Nowak, D. Leupold, W. Beenken, J. Ehlert, P. Hoffmann, H. Lokstein, Biochim. Biophys. A. 1321, 195 (1997)

Substructures and different energy relaxation time within the first electronic transition of pinacyanol, B. Voigt, F. Nowak, J. Ehlert, W. Beenken, D. Leupold, W. Sandner, Chem. Phys. Lett. 222, 380 (1997)

Analysis of ultrafast energy transfer by nonlinear polarization spectroscopy in the frequency domain, W. Beenken, J. Ehlert, B. Voigt, in Technical Digest UPS'97, Institute of Physics, University Tartu, 1997, pp. 42-43

Strong field theory of nonlinear polarization spectroscopy: Fundamentals and the two-level system, W. Beenken, V. May, J. Opt. Soc. Am. B 14, 2804 (1997)