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Lothar Weinhardt

Dr. Lothar Weinhardt

Head of Department X-ray Spectroscopy
lothar weinhardtOqy5∂kit edu


Dr. Lothar Weinhardt

Current position:
  • Head of department X-ray Spectroscopy
Previous position:
  • Scientist at the University of Würzburg
  • PosDoc at the University of Nevada, Las Vegas (UNLV)
  • Scientist and lecturer at the University of Würzburg
Field of research:
  • X-ray Spectroscopy
  • Development of instrumentation for synchrotron-based soft x-ray spectroscopy
  • Materials for energy
  • Soft x-ray Spectroscopy of liquids, solutions, and gases
Contributions to Monographs:

Marcus Bär, Lothar Weinhardt, and Clemens Heske; Chapter “Soft X-Ray and Electron Spectroscopy: A Unique Tool Chest to Characterize the Chemical and Electronic Properties of Surfaces and Interfaces” in “Advanced Characterization Techniques for Thin Film Solar Cells”, edited by D. Abou-Ras, Th. Kirchartz, and U. Rau, 1. Edition - March 2011, Wiley-VCH, Berlin.

C. Heske, L. Weinhardt, and M. Bär, Chapter “X-ray and electron spectroscopy studies of oxide semiconductors for photoelectrochemical hydrogen production” in “On Solar Hydrogen & Nanotechnology”, edited by L. Vayssieres, Wiley & Sons, Singapore, January 2010 (ISBN 978-0-47082-397-2).
Scientific Publications:

2017

R. Qiao, Q. Li, Z. Zhuo, S. Sallis, O. Fuchs, M. Blum, L. Weinhardt, C. Heske, J. Pepper, M. Jones, A. Brown, A. Spucces, K. Chow, B. Smith, P.-A. Glans, Y. Chen, S. Yan, F. Pan, L.F.J. Piper, J. Denlinger, J. Guo, Z. Hussain, Y.D. Chuang, W. Yang, “High-Efficiency in Situ Resonant Inelastic X-Ray Scattering (iRIXS) Endstation at the Advanced Light Source”, Rev. Sci. Instrum. 88, 33106 (2017).

A. Léon, A. Fiedler, M. Blum, A. Benkert, F. Meyer, W. Yang, M. Bär, F. Scheiba, H. Ehrenberg, L. Weinhardt, C. Heske, “Valence Electronic Structure of Li2O2, Li2O, Li2CO3, and LiOH Probed by Soft X-ray Emission Spectroscopy”, J. Phys. Chem. C 121, 5460 (2017).

Handick, P. Reinhard, R.G. Wilks, F. Pianezzi, Th. Kunze, D. Kreikemeyer-Lorenzo, L. Weinhardt, M. Blum, W. Yang, M. Gorgoi, E. Ikenaga, D. Gerlach, S. Ueda, Y. Yamashita, T. Chikyow, C. Heske, S. Buecheler, A.N. Tiwari, and M. Bär, “Formation of a K-In-Se Surface Species by NaF/KF Postdeposition Treatment of Cu(In,Ga)Se2 Thin-Film Solar Cell Absorbers”, ACS Appl. Mater. Interfaces 9, 3581 (2017).

M. Häming, T.T. Baby, S.K. Garlapati, B. Krause, H. Hahn, S. Dasgupta, L. Weinhardt, C. Heske, “The effect of NaCl on room-temperature-processed indium oxide nanoparticle thin films for printed electronics”, Appl. Surf. Sci. 396, 912 (2017).

2016

M. Mezher, R. Garris, L.M. Mansfield, M. Blum, D. Hauschild, K. Horsley, D.A. Duncan, W. Yang, M. Bär, L. Weinhardt, K. Ramanathan, and C. Heske, “Soft X-ray Spectroscopy of a Complex Heterojunction in High-Efficiency Thin-Film Photovoltaics: Intermixing and Zn Speciation at the Zn(O,S)/Cu(In,Ga)Se2 Interface”, ACS Appl. Mater. Interfaces 8, 33256 (2016).

M. Wallesch, A. Verma, Ch. Fléchon, H. Flügge, D.M. Zink, S. Seifermann, J.M. Navarro, T. Vitova, J. Göttlicher, R. Steininger, L. Weinhardt, M. Zimmer, M. Gerhards, C. Heske, S. Bräse, Th. Baumann, and D. Volz, “Towards Printed Organic Light-emitting Devices: A solution-stable, highly soluble Cu(I)-NHetPHOS-complex for inkjet processing”, Chem. Eur. J. 22, 16400 (2016).

D.A. Duncan, R. Mendelsberg, M. Mezher, K. Horsley, S.G. Rosenberg, M. Blum, G. Xiong, L. Weinhardt, M. Gloeckler, and C. Heske, “A New Look at the Electronic Structure of Transparent Conductive Oxides – A Case Study of the Interface between Zinc Magnesium Oxide and Cadmium Telluride”, Adv. Mater. Interfaces.  3, 1600418 (2016).

D. Hauschild, E. Handick, S. Gusenleitner‚ F. Meyer, H. Schwab, A. Benkert, S. Pohlner, J. Palm, S. Tougaard, C. Heske, L. Weinhardt, and F. Reinert, “Band-Gap Widening at the Cu(In,Ga)(S,Se)2 Surface: A Novel Determination Approach Using Reflection Electron Energy Loss Spectroscopy”, ACS Applied Materials & Interfaces 8, 21101 (2016).

Y.L. Jeyachandran, F. Meyer, S. Nagarajan, A. Benkert, M. Bär, M. Blum, W. Yang, F. Reinert, C. Heske, L. Weinhardt, and M. Zharnikov, “Investigation of the Ionic Hydration in Aqueous Salt Solutions by Soft X-ray Emission Spectroscopy”, J. Phys. Chem. B 120, 7687 (2016).

L. Weinhardt, O.Fuchs, A. Fischer, M. Weigand, F. Meyer, A. Benkert, M. Blum, M. Bär, S. Pookpanratana, J. Denlinger, C. Heske, and E. Umbach, “Site- and Symmetry-Resolved Resonant X-ray Emission Study of a Highly Ordered PTCDA Thin Film”, J. Phys. Chem. C 120, 8607 (2016).

A. Benkert, F. Meyer, D. Hauschild, M. Blum, W. Yang, R.G. Wilks, M. Bär, F. Reinert, C. Heske, and L. Weinhardt, “Isotope effects in the resonant inelastic soft x-ray scattering maps of gas-phase methanol”, J. Phys. Chem A 120, 2260 (2016).

M. Mezher, R. Garris, L.M. Mansfield, K. Horsley, L. Weinhardt, D.A. Duncan, M. Blum, S.G. Rosenberg, M. Bär, K. Ramanathan, and C. Heske, “Electronic Structure of the Zn(O,S)/Cu(In,Ga)Se2 Thin-Film Solar Cell Interface”, Prog. Photovolt: Res. Appl. 24, 1142 (2016).

M. Bär, N. Barreau, F. Couzinié-Devy, L. Weinhardt, R.G. Wilks, J. Kessler, and C. Heske, “Impact of annealing-induced intermixing on the electronic level alignment at the In2S3/Cu(In,Ga)Se2 thin-film solar cell interface”, ACS Applied Materials & Interfaces 8, 2120 (2016).

2015

L. Weinhardt, E. Ertan, M. Iannuzzi, M. Weigand, O. Fuchs, M. Bär, M. Blum, J.D. Denlinger, W. Yang, E. Umbach, M. Odelius, and C. Heske, “Probing hydrogen bonding orbitals: resonant inelastic soft x-ray scattering of aqueous NH3”, Phys. Chem. Chem. Phys. 17, 27145 (2015).

D.A. Duncan, J.M. Kephart, K. Horsley, M. Blum, M. Mezher, L. Weinhardt, M. Häming, R.G. Wilks, T. Hofmann, W. Yang, M. Bär, W.S. Sampath, and C. Heske, “Characterization of Sulfur Bonding in CdS:O Buffer Layers for CdTe-based Thin-Film Solar Cells”, ACS Appl. Mater. Interfaces 7, 16382 (2015).

D. Hauschild, F. Meyer, A. Benkert, D. Kreikemeyer-Lorenzo, S. Pohlner, J. Palm, M. Blum, W. Yang, R. G. Wilks, M. Bär, C. Heske, L. Weinhardt, and F. Reinert, “Annealing-Induced Effects on the Chemical Structure of the In2S3/CuIn(S,Se)2 Thin-Film Solar Cell Interface”, J. Phys. Chem. C 119, 10412 (2015).

D. Volz, Y. Chen, M. Wallesch, R. Liu, Ch. Fléchon, D.M. Zink, J. Friedrichs, H. Flügge, R. Steininger, J. Göttlicher, C. Heske, L. Weinhardt, S. Bräse, F. So, Th. Baumann, “Bridging the Efficiency Gap: Fully Bridged Dinuclear Cu(I)-Complexes for Singlet Harvesting in High-Efficiency OLEDs”, Adv. Mater. 27, 2538 (2015).

2014

F. Meyer, M.Blum, A. Benkert, D. Hauschild, S. Nagarajan, R.G. Wilks, W. Yang, M. Zharnikov, M. Bär, C. Heske, F. Reinert, and L. Weinhardt, “Building Block Picture” of the Electronic Structure of Aqueous Cysteine Derived from Resonant Inelastic Soft X-ray Scattering”, J. Phys. Chem. B 118, 13142 (2014).

Y.L. Jeyachandran, F. Meyer, S. Nagarajan, A. Benkert, M. Bär, M. Blum, W. Yang, F. Reinert, C. Heske, L. Weinhardt, and M. Zharnikov, “Ion-Solvation-Induced Molecular Reorganization in Liquid Water Probed by Resonant Inelastic Soft X-ray Scattering”, J. Phys. Chem. Lett. 5, 4143 (2014).

D. Volz, M. Wallesch, S. Grage, J. Göttlicher, R. Steininger, D. Batchelor, A. Ulrich, C. Heske, L. Weinhardt, T. Baumann, S. Bräse, “Labile or stable: Can homoleptic and heteroleptic PyrPHOS-copper complexes be processed from solution?", Inorganic Chemistry 53, 7837 (2014).

K. Horsley, R.J. Beal, R.G. Wilks, D.A. Hanks, M. Blum, M.G. Weir, M. Hӓming, T. Hofmann, L. Weinhardt, M. Bӓr, B.G. Potter, Jr., and C. Heske, “Impact of annealing on the chemical structure and morphology of the thin-film CdTe/ZnO interface”, J. Appl. Phys. 116, 024312 (2014).

D. Hauschild, F. Meyer, S. Pohlner, R. Lechner, R. Dietmüller, J. Palm, C.Heske, L. Weinhardt, F. Reinert, “Impact of environmental conditions on the chemical surface properties of Cu(In,Ga)(S,Se)2 thin-film solar cell absorbers”, J. Appl. Phys. 115, 183707  (2014).

A. Benkert, M. Blum, F. Meyer, R. G. Wilks, W. Yang, M. Bär, F. Reinert, C. Heske, and L. Weinhardt, “Novel setup for the in-situ investigation of gases and gas/solid interfaces by soft x-ray emission and absorption spectroscopy”, Rev. Sci. Instrum. 80, 015119 (2014).

2013

L. Weinhardt, M. Blum, O. Fuchs, S. Pookpanratana, K. George, B. Cole, B. Marsen, N. Gaillard, E. Miller, K.-S. Ahn, S. Shet, Y. Yan, M. M. Al-Jassim, J.D. Denlinger, W. Yang, M. Bär, and C. Heske, “Soft x-ray and electron spectroscopy to determine the electronic structure of materials for photoelectrochemical hydrogen production”, J. Electr. Spectr. Rel. Phenom. 190, 106 (2013).

M. Bär, S. Pookpanratana, L. Weinhardt, R.G. Wilks, B. Schubert, B. Marsen, T. Unold, M. Blum, S. Krause, Y. Zhang, F. Khan, A. Ranasinghe, K. Ramanathan, M.A. Contreras, S. Nishiwaki, X. Liu, N.R. Paudel, M. Morkel, O. Fuchs, T.P. Niesen, W. Yang, F. Karg, E. Umbach, A.D. Compaan, W.N. Shafarman, R. Noufi, H.-W. Schock, and C. Heske, “Soft x-rays shedding light on thin-film solar cell surfaces and interfaces”, J. Electr. Spectr. Rel. Phenom. 190, 47 (2013).

L. Weinhardt, M. Blum, O. Fuchs, A. Benkert, F. Meyer, M. Bär, J.D. Denlinger, W. Yang, F. Reinert, and C. Heske, “RIXS investigations of liquids, solutions, and liquid/solid interfaces”, J. Electr. Spectr. Rel. Phenom. 188, 111 (2013).

M. Bär, J. Klaer, L. Weinhardt, R.G. Wilks, S. Krause, M. Blum, W. Yang, C. Heske, and H.-W. Schock, “Cu2-xS surface phases and their impact on the electronic structure of CuInS2 thin films – a hidden parameter in solar cell optimization”, Advanced Energy Materials 3, 777 (2013).

W. Olovsson, L. Weinhardt, O. Fuchs, I. Tanaka, P. Puschnig, E. Umbach, C. Heske, and C. Ambrosch-Draxl, “The Be K-edge in beryllium oxide and chalcogenides: soft x-ray absorption spectra from first-principles theory and experiment”, J. Phys: Condens. Matt. 25, 315501 (2013).

T. Hofmann, T.H. Yu, M. Folse, L. Weinhardt, M. Bär, Y. Zhang (张宇锋), B.V. Merinov, D.J. Myers, W.A. Goddard III, and C. Heske, Reply to Comment on: “Using photoelectron spectroscopy and quantum mechanics to determine d-band energies of metals for catalytic applications” [J. Phys. Chem. C 116, 24016 (2012)], J. Phys. Chem. C 117, 6916 (2013).

M. Bär, J.-P. Theisen, R.G. Wilks, F. Erfurth, R. Félix, D. Gerlach, S. Haas, L. Tati Bismaths, F. Reinert, F. Kronast, T.P. Niesen, J. Palm, S. Visbeck, and L. Weinhardt, “Lateral inhomogeneity of the Mg/(Zn+Mg) composition at the (Zn,Mg)O/CuIn(S,Se)2 thin-film solar cell interface revealed by photoemission electron microscopy”, J. Appl. Phys. 113, 193709 (2013).

M. Bär, J. Klaer, R. Félix, N. Barreau, L. Weinhardt, R.G. Wilks, C. Heske, and H.-W. Schock, ”Surface Off-Stoichiometry of CuInS2 Thin-Film Solar Cell Absorbers“, J. Photovolt. 3, 828 (2013).

F. Meyer, L. Weinhardt, M.Blum, M. Bär, R.G. Wilks, W. Yang, C. Heske, and
F. Reinert, “Non-equivalent carbon atoms in the resonant inelastic soft X-ray scattering map of cysteine”, J. Chem. Phys. 138, 034306 (2013).

2012

M. Blum, M. Odelius, L. Weinhardt, S. Pookpanratana, M. Bär, Y. Zhang, O. Fuchs, W. Yang, E. Umbach, and C. Heske, “Ultra-fast proton dynamics in aqueous amino acid solutions studied by soft x-ray spectroscopy”, J. Phys. Chem B 116, 13757 (2012).

T. Hofmann, T.H. Yu, L.Weinhardt, M. Bär, Y. Zhang (张宇锋), B.V. Merinov, D. Myers, W.A. Goddard III, and C. Heske, “Using photoelectron spectroscopy and quantum mechanics to correlate d-band energies of metals with their catalytic activity”, J. Phys. Chem C 116, 24016 (2012).

H. Mahmoudi Chenari, L. Weinhardt, N.S. Rodriguez Lastra, M.A. Ernst,
F. Reinert, M.M. Golzan, A. Hassanzadeh, “Structural properties and x-ray photoelectron spectroscopy study of SnO2 nanoparticles”, Materials Letters 85, 168 (2012).

M. Bär, B.-A. Schubert, B. Marsen, R.G. Wilks, M. Blum, S. Krause, S. Pookpanratana, Y. Zhang, T. Unold, W. Yang, L. Weinhardt, C. Heske, and H.-W. Schock, “Cu2ZnSnS4 thin-film solar cell absorbers illuminated by soft x-rays“, J. Mater. Res. 27, 1097 (2012).

L. Weinhardt, A. Benkert, F. Meyer, M. Blum, R.G. Wilks, W. Yang, M. Bär, F. Reinert, and C. Heske, “Nuclear dynamics and spectator effects in resonant inelastic soft x-ray scattering of gas-phase water molecules”, J. Chem. Phys. 136, 144311 (2012). Selected for the Virtual Journal of Biological Physics Research 23 (2012).

S. Pookpanratana, R. France, R. Félix, R. Wilks, L. Weinhardt, T. Hofmann, L. Tati Bismaths, S. Mulcahy, F. Kronast, T. D. Moustakas, M. Bär, and C. Heske, “Microstructure of Vanadium-Based Contacts on n-type GaN”, J. Phys. D: Appl. Phys. 45,105401 (2012).

2011

M. Bär, B.-A. Schubert, B. Marsen, R.G. Wilks, S. Pookpanratana, M. Blum, S. Krause, T. Unold, W. Yang, L. Weinhardt, C. Heske, and H.-W. Schock, "Cliff-like conduction band offset and KCN-induced recombination barrier enhancement at the CdS/Cu2ZnSnS4 thin-film solar cell heterojunction”, Appl. Phys. Lett. 99, 222105 (2011).

J.M. Kinyanjui, D.W. Hatchett, G. Castruita, A.D. Ranasinghe, L. Weinhardt, T. Hofmann, and C. Heske, “Synthesis and Characterization of Conductive Polyimide/Carbon Composites with Pt Surface Deposits”, Synthetic Metals 161, 2368 (2011).

M. Bär, B.-A. Schubert, B. Marsen, S. Krause, S. Pookpanratana, T. Unold, L. Weinhardt, C. Heske, and H.-W. Schock, “Impact of KCN etching on the chemical and electronic surface structure of Cu2ZnSnS4 thin-film solar cell absorbers”, Appl. Phys. Lett. 99, 152111 (2011).

J.T. Sullivan, R.G. Wilks, M.T. Winkler, L. Weinhardt, D. Recht, A.J. Said, B.K. Newman, Y. Zhang, M. Blum, S. Krause, W.L. Yang, C. Heske, M.J. Aziz, M. Bär, and T. Buonassisi, “Soft X-Ray Emission Spectroscopy Studies of the Electronic Structure of Silicon Supersaturated with Sulfur”, Appl. Phys. Lett. 99, 142102 (2011).

M. Bär, B.-A. Schubert, B. Marsen, S. Krause, S. Pookpanratana, T. Unold, L. Weinhardt, C. Heske, and H.-W. Schock, “Native oxidation and Cu-poor surface structure of thin film Cu2ZnSnS4 solar cell absorbers”, Appl. Phys. Lett. 99, 112103 (2011).

L. Weinhardt, O. Fuchs, D. Batchelor, M. Bär, M. Blum, J.D. Denlinger, W. Yang, A. Schöll, F. Reinert, E. Umbach, and C. Heske, “Electron-hole correlation effects in core-level spectroscopy: The resonant inelastic soft x-ray scattering map of C60”, J. Chem. Phys 135, 104705 (2011).

L. Weinhardt, M. Weigand, O. Fuchs , M. Bär, M. Blum, J.D. Denlinger, W. Yang, E. Umbach, and C. Heske, “Nuclear dynamics in the core-excited state of aqueous ammonia probed by resonant inelastic soft x-ray scattering”, Phys. Rev. B 84, 104202 (2011).

M. Bär, B.-A. Schubert, B. Marsen, S. Schorr, R.G. Wilks, L. Weinhardt, S. Pookpanratana, M. Blum, S. Krause, Y. Zhang, W. Yang, T. Unold, C. Heske, and H.-W. Schock, “Electronic structure of Cu2ZnSnS4 probed by soft x-ray emission and absorption spectroscopy”, Phys. Rev. B 84, 035308 (2011).

M. Häming, L. Weinhardt, A. Schöll, F. Reinert, “Vibronic structure in resonant Auger Raman spectroscopy of large p-conjugated Molecules”, Chem. Phys. Lett. 510, 82 (2011).

F. Erfurth, A. Grimm, J. Palm, T.P. Niesen, F. Reinert, L. Weinhardt, and E. Umbach, “Direct determination of the band alignment at the (Zn,Mg)O/CISSe interface”, Appl. Phys. Lett. 98, 142107 (2011).

2010

Y. Zhang, G. Gajjala, T. Hofmann, L. Weinhardt, M. Bär, and C. Heske, M. Seelmann-Eggebert, and P. Meisen, “X-ray photoelectron spectroscopy study of the chemical interaction at the Pd/SiC interface”, J. Appl. Phys. 108, 093702 (2010).

S. Pookpanratana, X. Liu, N. R. Paudel, L. Weinhardt, M. Bär, Y. Zhang, A. Ranasinghe, F. Khan, M. Blum, W. Yang, A. Compaan, and C. Heske, “Effects of post-deposition treatments on surfaces of CdTe/CdS solar cells”, Appl. Phys. Lett. 97, 172109 (2010).

S. Pookpanratana, I. Repins, M. Bär, L. Weinhardt, Y. Zhang, R. Félix, M. Blum, W. Yang, R. Noufi, M. A. Contreras, and C. Heske, “CdS/Cu(In,Ga)Se2 interface formation in high-efficiency thin film solar cells”, Appl. Phys. Lett. 97, 074101(2010).

M. Bär, M. Wimmer, R.G. Wilks, M. Roczen, D. Gerlach, F. Ruske, K. Lips, B. Rech, L. Weinhardt, M. Blum, S. Pookpanratana, S. Krause, Y. Zhang, C. Heske, W. Yang, J.D. Denlinger, “Impact of solid-phase crystallization of amorphous silicon on the chemical structure of the buried Si/ZnO thin film solar cell interface”, Appl. Phys. Lett. 97, 072105 (2010).

S. Pookpanratana, R. France, M. Blum, A. Bell, M. Bär, L. Weinhardt, Y. Zhang, T. Hofmann, O. Fuchs, W. Yang, J. D. Denlinger, S. Mulcahy, T. D. Moustakas, and C. Heske, “Chemical structure of vanadium-based contact formation on n-AlN“, J. Appl. Phys. 108, 024906 (2010).

L. Weinhardt, M. Bär, M. Morkel, T.P. Niesen, F. Karg, K. Ramanathan, M. Contreras, R. Noufi, C. Heske, and E. Umbach, “Sulfur gradient driven Se diffusion at the CdS/CuIn(S,Se)2 interface in thin film solar cells”, Appl. Phys. Lett. 96, 182102 (2010).

M. Bär, N. Barreau, F. Couzinié-Devy, S. Pookpanratana, J. Klaer, M. Blum, Y. Zhang, W. Yang, J.D. Denlinger, H.-W. Schock, L. Weinhardt, J. Kessler, and C. Heske, “Non-destructive depth-resolved spectroscopic investigation of the heavily intermixed In2S3/Cu(In,Ga)Se2 interface”, Appl. Phys. Lett. 96, 184101 (2010).

I. Tran, R. Felix, M. Bär, L. Weinhardt, Y. Zhang, and C. Heske, “Oxidation of Ti-decorated Single-walled Carbon Nanotubes and subsequent reduction by Lithium”, JACS 132, 5789 (2010).

L. Weinhardt, O. Fuchs, M. Blum, M. Bär, M. Weigand, J.D. Denlinger, Y. Zubavichus, M. Zharnikov, M. Grunze, C. Heske, and E. Umbach, “Resonant x-ray emission spectroscopy of liquid water: novel instrumentation, high resolution, and the “map” approach”, J. Electr. Spectr. Rel. Phenom. 177, 206 (2010).

M. Bär, L. Weinhardt, B. Cole, B. Marsen, N. Gaillard, E.L. Miller, and C. Heske, “Mo incorporation in WO3 thin film photoanodes: Tailoring the electronic structure for photoelectrochemical hydrogen production”, Appl. Phys. Lett. 96, 032107 (2010).

N. Gaillard, B. Cole, B. Marsen, J. Kaneshiro, E.L. Miller, L. Weinhardt, M. Bär, C. Heske, K. -S. Ahn, Y. Yan, and M. M. Al-Jassim, “Origin of improved current collection in WO3:Mo/WO3 bilayer photoelectrodes”, J. Mater. Res. 25, 45 (2010).

2009

M. Blum, L. Weinhardt, O. Fuchs, M. Bär, Y. Zhang, M. Weigand, S. Krause, S. Pookpanratana, T. Hofmann, W. Yang, J. D. Denlinger, E. Umbach, and C. Heske, “Solid and liquid spectroscopic analysis (SALSA) – a soft x-ray spectroscopy endstation with a novel flow-through liquid cell“, Rev. Sci. Instr. 80, 123102 (2009).

M. Rusu, M. Bär, S. Lehmann, S. Sadewasser, L. Weinhardt, C.A. Kaufmann, E. Strub, J. Röhrich, W. Bohne, I. Lauermann, Ch. Jung, C. Heske, and M. Ch. Lux-Steiner, “Three-dimensional structure of the buffer/absorber interface in CdS/CuGaSe2 based thin film solar cells“, Appl. Phys. Lett. 95, 173502 (2009).

F. Erfurth, B. Hußmann, A. Schöll, F. Reinert, A. Grimm, I. Lauermann, M. Bär, Th. Niesen, J. Palm, S. Visbeck, L. Weinhardt, E. Umbach, “Chemical structure of the (Zn1-x,Mgx)O/CuIn(S,Se)2 interface in thin film solar cells”, Appl. Phys. Lett. 95, 122104 (2009).

M. Bär, I. Repins, M.A. Contreras, L. Weinhardt, R. Noufi, and C. Heske, “Chemical and electronic surface structure of 20%-efficient Cu(In,Ga)Se2 thin film solar cell absorbers”, Appl. Phys Lett. 95, 052106 (2009).

O. Fuchs, L. Weinhardt, M. Blum, M. Weigand, E. Umbach, M. Bär, C. Heske, J. Denlinger, Y.-D. Chuang, W. McKinney, Z. Hussain, E. Gullikson, M. Jones, P. Batson, B. Nelles, and R. Follarth, “High-Resolution, high-transmission soft x-ray spectrometer for the study of biological samples”, Rev. Sci. Instrum. 80, 063103 (2009).

L. Weinhardt, O. Fuchs, A. Fleszar, M. Bär, M. Blum, M. Weigand, J.D. Denlinger, W. Yang, W. Hanke, E. Umbach, and C. Heske, “Resonant inelastic soft x-ray scattering of CdS: A two-dimensional electronic structure map approach”, Phys. Rev. B 79, 165305 (2009).

M. Bär, K.-S. Ahn, S. Shet, Y. Yan, L. Weinhardt, O. Fuchs, M. Blum, S. Pookpanratana, K. George, W. Yang, J.D. Denlinger, M. Al-Jassim, and C. Heske, “Impact of air-exposure on the chemical and electronic structure of ZnO:Zn3N2 thin films”, Appl. Phys. Lett. 94, 012110 (2009).

2008

M. Bär, L. Weinhardt, S. Pookpanratana, and C. Heske, S. Nishiwaki and W. Shafarman, O. Fuchs, M. Blum, W. Yang, and J.D. Denlinger, “Depth-resolved band gap in Cu(In,Ga)(S,Se)2 thin films”, Appl. Phys. Lett. 93, 244103 (2008).

S. Pookpanratana, M. Bär, L. Weinhardt, C. Heske, R. France, T. D. Moustakas, O. Fuchs, M. Blum, W. Yang, and J. D. Denlinger, “Intermixing and chemical structure at the interface between n-GaN and V-based contacts”, Appl. Phys. Lett. 93, 172106 (2008).

M. Bär, L. Weinhardt, C. Heske, S. Nishiwaki, and W. N. Shafarman, “Chemical structure of the Cu(In,Ga)Se2/Mo and Cu(In,Ga)(S,Se)2/Mo interfaces”, Phys. Rev. B 78, 075404 (2008).

M. Bär, L. Weinhardt, S. Pookpanratana, C. Heske, S. Nishiwaki, and W. Shafarman, “Electronic level alignment at the deeply buried absorber/Mo interface in chalcopyrite-based thin film solar cells”, Appl. Phys. Lett. 93, 042110 (2008).

O. Fuchs, M. Zharnikov, L. Weinhardt, M. Blum, M. Weigand, Y. Zubavichus, M. Bär, F. Maier, W. Yang, J. D. Denlinger, C. Heske, M. Grunze, and E. Umbach, Reply to Comment on "Isotope and temperature effects in liquid water probed by x-ray absorption and resonant x-ray emission spectroscopy", Phys. Rev. Lett. 100, 249802 (2008).

L. Weinhardt, M. Blum, M. Bär, C. Heske, B. Cole, B. Marsen, and E.L. Miller, ”Electronic surface level positions of WO3 thin films for photoelectrochemical hydrogen production“, J. Phys. Chem. C 112, 3078 (2008).

O. Fuchs, F. Maier, L. Weinhardt, M. Weigand, M. Blum, M. Zharnikov, J. Denlinger, M. Grunze, C. Heske, and E. Umbach,“A liquid flow cell to study the electronic structure of liquids with soft X-rays”, Nucl. Instrum. Meth. A 585, 172 (2008).

O. Fuchs, M. Zharnikov, L. Weinhardt, M. Blum, M. Weigand, Y. Zubavichus, M. Bär, F. Maier, W. Yang, J. D. Denlinger, C. Heske, M. Grunze, and E. Umbach, "Isotope and temperature effects in liquid water probed by x-ray absorption and resonant x-ray emission spectroscopy", Phys. Rev. Lett. 100, 027801 (2008).

2007

L. Weinhardt, O. Fuchs, E. Umbach, C. Heske, A. Fleszar, W. Hanke, and J.D. Denlinger, “Resonant inelastic soft x-ray scattering, x-ray absorption spectroscopy, and density functional theory calculations of the electronic band structure of CdS”, Phys. Rev. B 75, 165207 (2007).

L. Weinhardt, M. Blum, M. Bär, C. Heske, O. Fuchs, E. Umbach, J.D. Denlinger, K. Ramanathan, and R. Noufi, "Chemical properties of the Cu(In,Ga)Se2/Mo/glass interfaces in thin film solar cells", Thin Solid Films 515, 6119-6122 (2007).

2006

M. Bär, A. Ennaoui, J. Klaer, R. Sáez-Araoz, T. Kropp, L. Weinhardt, C. Heske. H.-W. Schock, Ch.-H. Fischer, M.C. Lux-Steiner, “The electronic structure of the [Zn(S,O)/ZnS]/CuInS2 heterointerface – Impact of post-annealing”, Chem. Phys. Lett. 433, 71 (2006).

M. Bär, L. Weinhardt, C. Heske, H.-J. Muffler, E. Umbach, M.Ch. Lux-Steiner, Th. P. Niesen, F. Karg, and Ch.-H. Fischer, "Chemical insights into the Cd2+/NH3-treatment – an approach to explain the formation of Cd-compounds on Cu(In,Ga)(S,Se)2 absorbers", Solar Energy Materials and Solar Cells 90, 3151 (2006).

L. Weinhardt, O. Fuchs, D. Groß, E. Umbach, C. Heske, N.G. Dhere, A.A. Kadam, and S.S. Kulkarni, "Surface modifications of Cu(In,Ga)S2 thin film solar cell absorbers by KCN and H2O2/H2SO4 treatments", J. Appl. Phys. 100, 024907 (2006).

D. Eich, O. Fuchs, U. Groh, L. Weinhardt, R. Fink, E. Umbach, C. Heske, A. Fleszar, W. Hanke, E.K.U. Gross, C. Bostedt, T. van Buuren, N. Franco, L.J. Terminello, M. Keim, G. Reuscher, H. Lugauer, and A. Waag, "Resonant inelastic soft x-ray scattering of Be chalcogenides“, Phys. Rev. B 73, 115212 (2006).

L. Weinhardt, O. Fuchs, A. Peter, E. Umbach, C. Heske, J. Reichardt, M. Bär, I. Lauermann, I. Kötschau, A. Grimm, A. Sokoll, M.Ch. Lux-Steiner, Ch. Jung, W. Gudat, T. P. Niesen, and F. Karg, “Spectroscopic investigation of the deeply buried Cu(In,Ga)(S,Se)2/Mo interface in thin film solar cells”, J. Chem. Phys. 124, 074705 (2006).

2005

N.G. Dhere, A.A. Kadam, A.H. Jahagirdar, S.S. Kulkarni, L. Weinhardt, D. Groß, C. Heske, and E. Umbach, “Spectroscopic analysis of CIGS2/CdS thin film solar cell heterojunctions on stainless steel foil”, Journal of Physics and Chemistry of Solids 66, 1872-1875 (2005).

M. Bär, L. Weinhardt, C. Heske, H.-J. Muffler, M. Ch. Lux-Steiner, E. Umbach, and Ch.-H. Fischer, "Cd2+/NH3-treatment of Cu(In,Ga)(S,Se)2 thin film solar cell absorbers – a model for the performance-enhancing processes in the partial electrolyte", Prog. Photovolt. 13, 571-577 (2005).

M. Bär, J. Reichardt, A. Grimm, I. Kötschau, I. Lauermann, K. Rahne, S. Sokoll, M.C. Lux-Steiner, Ch.-H. Fischer, L. Weinhardt, E. Umbach, C. Heske, Ch. Jung, T.P. Niesen, and S. Visbeck, "The Zn(O,OH) material system in chalcopyrite thin film solar cells: Position of the valence band maximum vs. composition", J. Appl. Phys. 98, 053702 (2005).

M. Odelius, H. Ogasawara, D. Nordlund, O. Fuchs, L. Weinhardt, F. Maier, E. Umbach, C. Heske, Y. Zubavichus, M. Grunze, J.D. Denlinger, L.G.M. Pettersson, and A. Nilsson, "Ultra-fast Dynamics in Water probed by X-ray Emission Spectroscopy", Phys. Rev. Lett. 94, 227401 (2005).

M. Bär, S. Lehmann, M. Rusu, A. Grimm, I. Kötschau, I. Lauermann, P. Pistor, S. Sokoll, Th. Schedel-Niedrig, M.C. Lux-Steiner, Ch.-H. Fischer, L. Weinhardt, C. Heske, and Ch. Jung, "Cd2+/NH3 – Treatment Induced Formation of a CdSe Surface Layer on CuGaSe2 Thin Film Solar Cell Absorbers", Appl. Phys. Lett. 86, 222107 (2005).

J. Reichardt, M. Bär, A. Grimm, I. Kötschau, I. Lauermann, S. Sokoll, M. C. Lux-Steiner, Ch.-H. Fischer, C. Heske, L. Weinhardt, O. Fuchs, Ch. Jung, W. Gudat, and F. Karg, "Inducing and monitoring photoelectrochemical reactions at surfaces and buried interfaces in Cu(In,Ga)(S,Se)2 thin film solar cells", Appl. Phys. Lett. 86, 172102 (2005).

L. Weinhardt, O. Fuchs, D. Groß, G. Storch, E. Umbach, N.G. Dhere, A.A. Kadam, S.S. Kulkarni, and C. Heske, "Band alignment at the CdS/Cu(In,Ga)S2 interface in thin film solar cells", Appl. Phys. Lett. 86, 062109 (2005).

2004

Y. Zubavichus, M. Zharnikov, A. Shaporenko, O. Fuchs, L. Weinhardt, C. Heske, E. Umbach, J.D. Denlinger, and M. Grunze, "Soft X-ray induced decomposition of phenylalanine and tyrosine: a comparative study", J. Phys. Chem. A 108, 4557-4565 (2004).

L. Weinhardt, C. Heske, E. Umbach, T.P. Niesen, S. Visbeck, and F. Karg, "Band alignment at the i-ZnO/CdS interface in Cu(In,Ga)(S,Se)2 thin film solar cells", Appl. Phys. Lett. 84, 3175-3177 (2004).

Y. Zubavichus, M. Grunze, O. Fuchs, L. Weinhardt, C. Heske, E. Umbach, and J. D. Denlinger, "Soft X-ray induced decomposition of amino acids: a time-resolved XPS, mass-spectrometry, and NEXAFS study”, Radiat. Res. 161, 346-358 (2004).

T. Strunskus, O. Fuchs, L. Weinhardt, C. Heske, M. Guraya, M. Muhler, V. Staemmler, and Ch. Wöll, "The valence electronic structure of zinc oxide powders as determined by X-ray emission spectroscopy: variation of electronic structure with particle size", J. Electron Spectrosc. Rel. Phenom. 134, 183-189 (2004).

2003

Ch. Barglik-Chory, D. Buchold, M. Schmitt, W. Kiefer, C. Heske, C. Kumpf, O. Fuchs, L. Weinhardt, A. Stahl, E. Umbach, M. Lentze, J. Geurts, and G. Müller, "Synthesis, structure, and spectroscopic characterization of water-soluble CdS nanoparticles", Chem. Phys. Lett. 379, 443-451 (2003).

I. Lauermann, M. Bär, A. Ennaoui, U. Fiedeler, C.-H. Fischer, A. Grimm, I. M. Kötschau, M. C. Lux-Steiner, J. Reichardt, B. R. Sankapal, S. Siebentritt, S. Sokoll, L. Weinhardt, O. Fuchs, C. Heske, C. Jung, W. Gudat, F. Karg, and T. P. Niesen, "Analysis of zinc compound buffer layers in Cu(In,Ga)(S,Se)2 thin film solar cells by synchrotron-based soft X-ray spectroscopy", Mat. Res. Soc. Symp. Proc. Vol. 763, ISBN 1-55899-700-8, p. 610-613 (2003).

A. Meeder, L. Weinhardt, R. Stresing, D. Fuertes Marrón, R. Würz, S.M. Babu, T. Schedel-Niedrig, M.Ch. Lux-Steiner, C. Heske, and E. Umbach, "Surface and bulk properties of CuGaSe2 thin films“, J. of Phys. and Chem. of Solids 64, 1553-1557 (2003).

C. Heske, U. Groh, O. Fuchs, L. Weinhardt, E. Umbach, Th. Schedel-Niedrig, Ch.-H. Fischer, M.Ch. Lux-Steiner, S. Zweigart, F. Karg, J.D. Denlinger, B. Rude, C. Andrus, and F. Powell, "Monitoring chemical reactions on surfaces in liquids: water on CuIn(S,Se)2 thin film solar cell

absorbers", J. Chem. Phys. (Comm.) 119, 10467-10470 (2003).

C. Heske, U. Groh, O. Fuchs, L. Weinhardt, E. Umbach, M. Grün, S. Petillon, A. Dinger, C. Klingshirn, W. Szuszkiewicz, and A. Fleszar, “Studying the local chemical environment of sulfur atoms at buried interfaces in CdS/ZnSe superlattices“, Appl. Phys. Lett. 83, 2360-2362 (2003).

Th. Gleim, L. Weinhardt, Th. Schmidt, R. Fink, C. Heske, E. Umbach, L. Hansen, G. Landwehr, A. Waag, A. Fleszar, B. Richter, Ch. Ammon, M. Probst, and H.-P. Steinrück, "The influence of As-passivation on the electronic level alignment at BeTe/Si(111)-interfaces“, Phys. Rev. B 67, 205315 (2003).

L. Weinhardt, M. Bär, H.-J. Muffler, Ch.-H. Fischer, M.C. Lux-Steiner, T.P. Niesen, F. Karg, Th. Gleim, C. Heske, and E. Umbach, "Impact of Cd2+-treatment on the band alignment at the ILGAR-ZnO/CuIn(S,Se)2 heterojunction”, Thin Solid Films 431-432, 272-276 (2003).

A.S. Ethiraj, N. Hebalkar, S.K. Kulkarni, R. Pasricha, J. Urban, C. Dem, M. Schmitt, W. Kiefer, L. Weinhardt, S. Joshi, R. Fink, C. Heske, C. Kumpf, and E. Umbach, "Enhancement of photoluminescence in manganese doped ZnS nanoparticles due to a silica shell”, J. Chem. Phys. 118, 8945-8953 (2003). Selected for the Virtual Journal of Nanoscale Science & Technology 7(19), 2003.

L. Weinhardt, Th. Gleim, O. Fuchs, C. Heske, E. Umbach, M. Bär, H.-J. Muffler, Ch.-H. Fischer, M.C. Lux-Steiner, Y. Zubavichus, T.P. Niesen, and F. Karg, “CdS- and Cd(OH)2-formation during Cd-treatments of Cu(In,Ga)(S,Se)2 thin film solar cell absorbers”, Appl. Phys. Lett. 82, 571-573 (2003).

2002

C. Heske, U. Groh, L. Weinhardt, O. Fuchs, B. Holder, E. Umbach, C. Bostedt, L.J. Terminello, S. Zweigart, T.P. Niesen, and F. Karg, "Damp-heat induced sulfate formation in Cu(In,Ga)(S,Se)2–based thin film solar cells”, Appl. Phys. Lett. 81, 4550-4552 (2002).

Th. Gleim, L. Weinhardt, Th. Schmidt, R. Fink, C. Heske, E. Umbach, P. Grabs, G. Schmidt, L.W. Molenkamp, B. Richter, A. Fleszar, and H.-P. Steinrück, "Energy level alignment at zincblende Cd(Mn)Se/ZnTe/InAs(100) interfaces“, Appl. Phys. Lett. 81, 3813-3815 (2002).

2001

M. Morkel, L. Weinhardt, B. Lohmüller, C. Heske, E. Umbach, W. Riedl, S. Zweigart, and  F. Karg, "Flat conduction band alignment at the CdS/CuInSe2 thin film solar cell heterojunction", Appl. Phys. Lett. 79, 4482-4484 (2001).