2025
[69] M. A. Gonzalez‐Angulo, V. N. Mitryakhin, M. Axt, D. Pareek, L. Gütay, M. Silies, T. Leißner, U. Höfer, S. Schäfer, C. Schneider, Second Harmonic Characteristics of Large‐Area ALD‐Grown MoS2 Monolayers and MoS2/WS2 Heterostructures with Sub‐Millimeter Crystalline Orientation, Adv. Mat. Interfaces 12, e00480 (2025). (externer Link, öffnet neues Fenster)
[68] X. Xing, F. Wen, S. Schafer, D. Zhong, Vibrational Dynamics in Black Phosphorus Membranes Visualized by Ultrafast Electron Microscopy, J. Phys. Chem. Lett. 16, 12246 (2025). (externer Link, öffnet neues Fenster)
[67] A. Kovács, J. T. Weber, M. Charilaou, D. Kong, L. Prodan, V. Tsurkan, A. Schröder, N. S. Kiselev, I. Kézsmárki, R. E. Dunin-Borkowski, A. H. Tavabi, S. Schäfer, All-optical stochastic switching of magnetization textures in Fe3Sn2, Communication Materials 6,223 (2025). (externer Link, öffnet neues Fenster)
[66] A. Schröder, A. Wendeln, J. T. Weber, M. Mukai, Y. Kohno, and S. Schäfer, Laser-driven cold-field emission source for ultrafast transmission electron microscopy, Ultramicroscopy 275, 114158 (2025). (externer Link, öffnet neues Fenster)
[65] N. Müller, G. Vosse, F. Evers, and S. Schäfer, Inelastic Electron-Light Scattering at Dielectric Thin Films, arXiv:2405.11495.
[64] N. Müller, S. El Kabil, G. Vosse, L. Hansen, C. Rathje, and S. Schäfer, Spectrally Resolved Free Electron-Light Coupling Strength in a Transition Metal Dichalcogenide, arXiv:2405.12017.
[63] J. T. Weber, N. Müller, A. Schröder, and S. Schäfer, Visualizing Standing Light Waves in Continuous-Beam Transmission Electron Microscopy, ACS Photonics 12, 819 (2025). (externer Link, öffnet neues Fenster)
2024
[62] S. Schäfer, S. Heiles, R. Schäfer, On the dipole moment distribution of rigid symmetric rotors. J. Chem. Phys. 161, 044312 (2024). (externer Link, öffnet neues Fenster)
[61] J. T. Weber, S. Schäfer, Electron imaging of nanoscale charge distributions induced by femtosecond light pulses. Nano Lett. 24, 5746 (2024). (externer Link, öffnet neues Fenster)
[60] A. Ungeheuer, N. Bach, M. T. Mir, A. S. Hassanien, L. Nöding, T. Baumert, S. Schäfer, A. Senftleben. Coherent acoustic phonons in coupled hexagonal boron nitride-graphite heterostructure. Struct. Dyn. 11, 014501 (2024) (externer Link, öffnet neues Fenster).
[59] A. Schröder, Chr. Rathje, L. van Velzen, M. Kelder, S. Schäfer, Improving the temporal resolution of event-based electron detectors using neural network cluster analysis. Ultramicroscopy 256, 113881 (2023) (externer Link, öffnet neues Fenster).
2023
[58] Chr. Rathje, R. von Seggern, L. A. Gräper, J. Kredl, J. Walowski, M. Münzenberg, S. Schäfer. Coupling broadband terahertz dipoles to microscale resonators. ACS Photonics 10, 3467 (2023) (externer Link, öffnet neues Fenster).
[57] N. Müller, S. Schäfer. Of Electrons and Photons, News and Views: Of electrons and photons. Nature Physics 19, 1239 (2023) (externer Link, öffnet neues Fenster).
2022
[56] N. Bach, A. Feist, M. Möller, C. Ropers, S. Schäfer, Tailored nanophononic wavefield in a patterned bilayer system probed by ultrafast convergent beam electron diffraction. Structural Dynamics 9, 034301 (2022) (externer Link, öffnet neues Fenster).
[55] D. Pareek, M. A. Gonzalez, N. Grewo, M. L. Janßen, K. Arunakiri, K. Luqman Alimi, M. Silies, J. Parisi, L. Gütay, S. Schäfer. Large-Area Growth of MoS2/WS2 Heterostructures by a sequential atomic layer deposition and spin-coating approach. Adv. Mater. Interfaces 9, 2200816 (2022) (externer Link, öffnet neues Fenster).
[54] C. Lattyak, M. Vehse, M. A. Gonzalez, D. Pareek, L. Gütay, S. Schäfer, C. Agert. Optoelectronic properties of MoS2 in proximity to carrier selective metal oxides. Adv. Opt. Mater. 10, 2102226 (2022) (externer Link, öffnet neues Fenster).
2021
[53] A. Hariharan, S. Schäfer, S. J. Heise. Decay of excess carriers in a two-defect model semiconductor: A time-resolved photoluminescence study. J. Appl. Phys. 130, 235702 (2021) (externer Link, öffnet neues Fenster).
[52] H. Ahmed, V. Solovyeva, M. A. Gonzalez, M. Elshabasi, M. Richter, D. Pareek, S. J. Heise, M. Stölzel, A. Weber, Th. Dalibor, S. Schäfer, J. Parisi. Impact of the buffer/absorber interface on the metastability of fill factor temperature coefficients in CIGSSe solar cells. Adv. Mat. Interfaces. 18, 2100778 (2021) (externer Link, öffnet neues Fenster).
[51] N. Bach, S. Schäfer. Ultrafast strain propagation and acoustic resonances in nanoscale bilayer systems. Structural Dynamics 8, 035101 (2021) (externer Link, öffnet neues Fenster).
[50] D. Pareek, K. G. Roach, M. A. Gonzalez, L. Büsing, J. Parisi, L. Gütay, S. Schäfer, Micro-patterned deposition of MoS2 ultrathin-films by a controlled droplet dragging approach. Scientific Reports, 11, 13993 (2021) (externer Link, öffnet neues Fenster).
[49] T. Harvey, N. Rubiano, J. H. Gaida, M. Möller, A. Feist, S. Schäfer, C. Ropers, Ultrafast electron microscopy for probing magnetic dynamics. MRS Bulletin 46, 711 (2021) (externer Link, öffnet neues Fenster).
[48] M. A. Gonzalez, D. Pareek, L. Büsing, M. Beer, J. Parisi, S. Schäfer, L. Gütay, Rapid formation of large area MoS2 monolayers by a parameter resilient atomic layer deposition approach, APL Materials 9, 051122 (2021) (externer Link, öffnet neues Fenster).
[47] H. Ahmed, M. Elshabasi, J. Ohland, M. Stölzel, A. Weber, R. Lechner, Th. Dalibor, J. Parisi, S. Schäfer, S. J. Heise, Temperature coefficient characterization of CIGSSe solar cells with layer modifications. Solar Energy Materials and Solar Cells, 225, 111059 (2021) (externer Link, öffnet neues Fenster).
[46] N. Müller, V. Hock, C. Rathje, H. Koch, S. Schäfer, Broadband coupling of fast electrons to high-Q whispering gallery mode resonators. ACS Photonics 8 1569-1575 (2021) (externer Link, öffnet neues Fenster).
2020
[45] A. Feist, S.V. Yalunin, S. Schäfer, C. Ropers, High-purity free-electron momentum states prepared by three-dimensional optical phase modulation. Phys. Rev. Research 2, 043227 (2020) (externer Link, öffnet neues Fenster).
[44] P. Dombi, Z. Pápa, J. Vogelsang, S. V. Yalunin, M. Sivis, G. Herink, S. Schäfer, P. Gross, C. Ropers, Ch. Lienau. Strong-field nano-optics. Rev. Mod. Phys. 92, 025003 (2020) (externer Link, öffnet neues Fenster).
[43] M. Möller, J.H. Gaida, S. Schäfer, C. Ropers. Few-nm tracking of current-driven magnetic vortex orbits using ultrafast Lorentz microscopy. Communications Physics 3, 1-7 (2020) (externer Link, öffnet neues Fenster).
[42] K. Eickhoff, Chr. Rathje, D. Köhnke, S. Kerbstadt, L. Englert, T. Bayer, S. Schäfer and M. Wollenhaupt. Orbital angular momentum superposition states in transmission electron microscopy and bichromatic multiphoton ionization. New. J. Phys. 22, 103045 (2020) (externer Link, öffnet neues Fenster).
2019
[41] N. Bach, T. Domröse, A. Feist, T. Rittmann, S. Strauch, C. Ropers, S. Schäfer. Coulomb interactions in high-coherence femtosecond electron pulses from tip emitters. Struct. Dyn. 6, 014301 (2019). (externer Link, öffnet neues Fenster)
[40] D. Pareek, M. A. Gonzalez, J. Zohrabian, M. H. Sayed, V. Steenhoff, C. Lattyak, M. Vehse, C. Agert, J. Parisi S. Schäfer, L. Gütay. A vapor-phase-assisted growth route for large-scale uniform deposition of MoS2 monolayer films. RSC Advances 9, 107-113 (2019). (externer Link, öffnet neues Fenster)
2018
[39] N. Rubiano da Silva, M. Möller, A. Feist, H. Ulrichs, C. Ropers, S. Schäfer. Nanoscale mapping of ultrafast magnetization dynamics with femtosecond Lorentz microscopy. Phys. Rev. X 8, 031052 (2018). (externer Link, öffnet neues Fenster)
[38] A. Feist, G. Storeck, S. Schäfer, C. Ropers. Structural dynamics probed by high-coherence electron pulses. MRS Bulletin 43, 505 (2018). (externer Link, öffnet neues Fenster)
[37] A. Feist, N. Rubiano da Silva, W. Liang, C. Ropers, S. Schäfer. Nanoscale diffractive probing of strain dynamics in ultrafast transmission electron microscopy. Struct. Dyn. 5, 014302 (2018). (externer Link, öffnet neues Fenster)
[36] S. Vogelgesang, G. Storeck, S. Schramm, K. Rossnagel, S. Schäfer, C. Ropers. Phase ordering of charge density waves traced by ultrafast low-energy electron diffraction. Nature Physics 14, 184 (2018) (externer Link, öffnet neues Fenster).
2017
[35] O. Kfir, S. Zayko, C. Nolte, M. Sivis, M. Möller, B. Hebler, S. S. P. K. Arekapudi, D. Steil, S. Schäfer, M. Albrecht, O. Cohen, S. Mathias, C. Ropers. Tabletop Nanoscale Magnetic Imaging using High-Harmonic Radiation. Science Advances, 3, eaao4641 (2017). (externer Link, öffnet neues Fenster)
[34] K. E. Priebe, C. Rathje, S. V. Yalunin, Th. Hohage, A. Feist, S. Schäfer, C. Ropers. Attosecond electron pulse trains and quantum state reconstruction in ultrafast transmission electron microscopy. Nature Photonics 11, 793 (2017). (externer Link, öffnet neues Fenster)
[33] G. Storeck, S. Vogelgesang, M. Sivis, S. Schäfer, C. Ropers. Nanotip-based photoelectron microgun for ultrafast LEED. Struct. Dyn. 4, 044024 (2017) (externer Link, öffnet neues Fenster).
[32] Th. Danz, A. Neff, J. H. Gaida, R. Bormann, C. Ropers, S. Schäfer. Ultrafast sublattice pseudospin relaxation in graphene probed by polarization-resolved photoluminescence. Phys. Rev. B 95, 241412(R) (2017) (externer Link, öffnet neues Fenster).
[31] A. Feist, N. Bach, N. Rubiano da Silva, Th. Danz, M. Möller, K. E. Priebe, T. Domröse, J. G. Gatzmann, S. Rost, J. Schauss, S. Strauch, R. Bormann, M. Sivis, S. Schäfer, C. Ropers. Ultrafast transmission electron microscopy using a laser-driven field emitter: femtosecond resolution with a high coherence electron beam. Ultramicroscopy 176, 63-73 (2017). (externer Link, öffnet neues Fenster)
[30] T. Eggebrecht, M. Möller, J. G. Gatzmann, N. Rubiano da Silva, A. Feist, U. Martens, H. Ulrichs, M. Münzenberg, C. Ropers, S. Schäfer. Light induced metastable magnetic texture uncovered by in-situ Lorentz microscopy. Phys. Rev. Lett. 118, 097203 (2017). (externer Link, öffnet neues Fenster)
Featured in: Research Highlights, Nature Nanotech. 12, 286 (2017).
2016
[29] M. Gulde, A. Rissanou, V. Harmandaris, M. Müller, S. Schäfer, C. Ropers. Structure and dynamics of monolayer polymer crystallites on graphene. Nano Lett. 16, 6994–7000 (2016). (externer Link, öffnet neues Fenster)
[28] K. E. Echternkamp, A. Feist, S. Schäfer, C. Ropers. Ramsey-type phase control of free electron beams. Nature Phys. 12, 1000-1004 (2016). (externer Link, öffnet neues Fenster)
[27] S. Zayko, M. Sivis, S. Schäfer, C. Ropers. Polarization contrast of nanoscale waveguides in high-harmonic imaging. Optica 3, 239 (2016). (externer Link, öffnet neues Fenster)
[26] K. E. Echternkamp, G. Herink, S. V. Yalunin, K. Rademann, S. Schäfer, C. Ropers. Strong-field photoemission in nanotip near-fields: from quiver to sub-cycle electron dynamics. Appl. Phys. B 122, 1–10 (2016). (externer Link, öffnet neues Fenster)
2015
[25] B. Schröder, M. Sivis, R. Bormann, S. Schäfer, C. Ropers. An ultrafast nanotip electron gun triggered by grating-coupled surface plasmons. Appl. Phys. Lett. 107, 231105 (2015).
[24] R. Bormann, S. Strauch, S. Schäfer, C. Ropers. An ultrafast electron microscope gun driven by two-photon photoemission from a nanotip cathode. J. Appl. Phys. 118, 173105 (2015).
[23] B. Schröder, T. Weber, S. V. Yalunin, C. Matyssek, T. Kiel, M. Sivis, S. Schäfer, F. von Cube, S. Irsen, K. Busch, C. Ropers, S. Linden. Real space imaging of nanotip plasmons using electron energy-loss spectroscopy. Phys. Rev. B 92, 085411 (2015).
[22] S. Zayko, E. Mönnich, M. Sivis, D. Mai, T. Salditt, S. Schäfer, C. Ropers. Coherent diffractive imaging beyond the projection approximation: Waveguiding at extreme ultraviolet wavelengths. Opt. Exp. 23, 19911 (2015).
[21] A. Feist, K. Echternkamp, J. Schauss, S. V. Yalunin, S. Schäfer, C. Ropers. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope. Nature 521, 200–203 (2015).
Featured in: Mathieu Kociak. Microscopy: Quantum control of free electrons, Nature 521, 166-167 (2015), and R. Vogelgesang, J. Vogelsang, C. Lienau. Elektronen steuern mit Licht. Physik Journal, 06/2015.
2014
[20] M. Gulde, S. Schweda, G. Storeck, M. Maiti, H. K. Yu, A. M. Wodtke, S. Schäfer, C. Ropers. Ultrafast low-energy electron diffraction in transmission resolves polymer/graphene superstructure dynamics. Science 345, 200–204 (2014).
Featured in: Erik T. J. Nibbering. Low-energy electron diffraction at ultrafast speeds. Science 345, 137–138 (2014).
2012
[19] A. Paarmann, M. Gulde, M. Müller, S. Schäfer, S. Schweda, M. Maiti, C. Xu, T. Hohage, F. Schenk, C. Ropers, R. Ernstorfer. Coherent femtosecond low-energy single-electron pulses for time-resolved diffraction and imaging: a numerical study. J. Appl. Phys. 112, 113109 (2012).
[18] W. Liang, S. Schäfer, A. H. Zewail. Ultrafast electron crystallography of heterogeneous structures: gold-graphene bilayer and ligand-encapsulated nanogold on graphene. Chem. Phys. Lett. 542, 8–12 (2012).
[17] W. Liang, S. Schäfer, A. H. Zewail. Ultrafast electron crystallography of monolayer adsorbates on clean surfaces: structural dynamics. Chem. Phys. Lett. 542, 1–7 (2012).
[16] A. Yurtsever, S. Schäfer, A. H. Zewail. Ultrafast Kikuchi diffraction: nanoscale stress–strain dynamics of wave-guiding structures. Nano Lett. 12, 3772–3777 (2012).
[15] S. M. Kast, S. Schäfer, R. Schäfer. Thermally induced polarizabilities and dipole moments of small tin clusters. J. Chem. Phys. 136, 134320 (2012).
2011
[14] S. Schäfer, W. Liang, A. H. Zewail. Structural dynamics of surfaces by ultrafast electron crystallography: Experimental and multiple scattering theory. J. Chem. Phys., 135, 214201 (2011).
[13] S. Schäfer, W. Liang, A. H. Zewail. Structural dynamics of nanoscale gold by ultrafast electron crystallography. Chem. Phys. Lett. 515, 278–282 (2011).
[12] S. Heiles, S. Schäfer, R. Schäfer. On the rotational temperature and structure dependence of electric field deflection experiments: A case study of germanium clusters. J. Chem. Phys. 135, 034303 (2011).
[11] S. Schäfer, W. Liang, A. H. Zewail. Primary structural dynamics in graphite. New J. Phys. 13, 063030 (2011).
2010
[10] S. Schäfer, W. Liang, A. H. Zewail. Structural dynamics and transient electric-field effects in ultrafast electron diffraction from surfaces. Chem. Phys. Lett. 493, 11–18 (2010).
[9] B. Assadollahzadeh, S. Schäfer, P. Schwerdtfeger. Electronic properties for small tin clusters Snn (n≤ 20) from density functional theory and the convergence toward the solid state. J. Comp. Chem. 31, 929–937 (2010).
[8] S. Heiles, S. Schäfer, R. Schäfer. Mass spectrometry and beam deflection studies of tin–lead nanoalloy clusters. Phys. Chem. Chem. Phys. 12, 247–253 (2010).
2009
[7] U. Rohrmann, S. Schäfer, R. Schäfer. Size-and temperature-dependent magnetic response of molecular cage clusters: manganese-doped tin clusters. J. Phys. Chem. A 113, 12115–12121 (2009).
2008
[6] C. Thierfelder, B. Assadollahzadeh, P. Schwerdtfeger, S. Schäfer. R. Schäfer, Relativistic and electron correlation effects in static dipole polarizabilities for the group-14 elements from carbon to element Z= 114: Theory and experiment. Phys. Rev. A 78, 052506 (2008).
[5] S. Schäfer, B. Assadollahzadeh, M. Mehring, P. Schwerdtfeger, R. Schäfer. Structure and Electric Properties of SnN Clusters (N= 6− 20) from Combined Electric Deflection Experiments and Quantum Theoretical Studies. J. Phys. Chem. A 112, 12312–12319 (2008).
[4] S. Schäfer, R. Schäfer. New Molecular Cage Clusters of Pb by Encapsulation of Mg. ChemPhysChem 9, 1925–1929 (2008).
[3] S. Schäfer, S. Heiles, J. A. Becker, R. Schäfer. Electric deflection studies on lead clusters. J. Chem. Phys. 129, 44304–44304 (2008).
[2] S. Schäfer, R. Schäfer. Dielectric response of germanium clusters. Phys. Rev. B 77, 205211 (2008).
[1] S. Schäfer, M. Mehring, R. Schäfer, P. Schwerdtfeger. Polarizabilities of Ba and Ba2: Comparison of molecular beam experiments with relativistic quantum chemistry. Phys. Rev. A 76, 052515 (2008).