The Scientific Facility "Interface Analysis" (Grenzflächen Analytik, GA) (headed by Prof. Dr. Ulrich Starke) provides service (and facilities) to quantify the chemical composition and to determine the electronic structure and the atomic geometry of solid-solid and gas-solid interfaces.
Research in the Interface Analysis group is directed towards the atomic and electronic structure of surfaces and thin films of technologically interesting materials like graphene and transition metal dichalcogenides (TMDs). The goal of these research activities is a fundamental understanding of growth, interface and crystal formation and elecronic structure at the atomic scale. A major research project at present is the growth and manipulation of electronic properties of epitaxial graphene on SiC.

News

24/04/2024: New paper published in Nanoscale Advances on defect domains in multi-shape monolayer tungsten disulfide

H. Agircan, D. Convertino, A. Rossi, L. Martini, S. Pace, N. Mishra, K. Küster, U. Starke, G. Kartal Sireli, C. Coletti, S. Forti, Nanoscale Adv. (2024) DOI: 10.1039/d4na00125g, Determination and investigation of defect domains in multi-shape monolayer tungsten disulfide.

25/03/2024: New paper in Nature Communications on the self-intercalation of Nb_1+xSe₂ films

H. Wang, J. Zhang, C. Shen, C. Yang, K. Küster, J. Deuschle, U. Starke, H. Zhang, M. Isobe, D. Huang, P. A. van Aken, H. Takagi, Nat. Commun. 15, 2541 (2024), Direct visualization of stacking-selective self-intercalation in epitaxial Nb_1+xSe₂ films. 

24/07/2023: New paper of our FOR 5242 on the intercalation of Pb under epitaxial graphene published in Advanced Materials Interfaces

P. Schädlich, C. Gosal, M. Stettner, B. Matta, S. Wolff, F. Schölzel, P. Richter, M. Hutter, A. Haags, S. Wenzel, Z. Mamiyev, J. Koch, S. Soubatch, P. Rosenzweig, C. Polley, F. S. Tautz, C. Kumpf, K. Küster, U. Starke, T. Seyller, F. C. Bocqet, C. Tegenkamp, Adv. Mater. Interfaces 2300471 (2023). Domain boundary formation within an intercalated Pb monolayer featuring charge-neutral epitaxial graphene.

04/07/2023: Philipp Rosenzweig has defended his PhD thesis on “Intercalated epitaxial graphene on SiC: Tunbable doping across van Hove filling and comtrol of the emerging band structure at the interface” with distinction! Congratulations to Philipp!

3 papers published within one week. Not too bad!

29/6/2022: Interlayer coupling of 2H-NbS₂ published in Phys. Rev. B

D. Huang, H. Nakamura, K. Küster, U. Wedig, N. B. M. Schröter V. N. Strocov, U. Starke, H. Takagi, Phys. Rev B 105, 245145 (2022). Probing the interlayer coupling in 2H-NbS₂ via soft x-ray angle-resolved photoemission spectroscopy.

This paper was chosen as “Editors Suggestion” more

28/6/2022: Pb intercalated graphene on SiC published in Phys. Rev. Research

B. Matta, P. Rosenzweig, O. Bolkenbaas, K. Küster, U. Starke, Phys. Rev. Reserach 4, 023250. Momentum microscopy of Pb-intercalated graphene on SiC: Charge neutrality and electronic structure of interfacial Pb.

This paper was chosen as “Editors Suggestion” more

22/06/2022: charge-transfer doping of silver monolayer beneath epitaxial graphene published in Phys. Rev. B.

P. Rosenzweig, H. Karakachian, D. Marchenko, U. Starke, Phys. Rev. B 105, 236528 (2022). Surface charge-transfer doping a quantum-confined silver monolayer beneath epitaxial graphene.

31/02/2022: periodic pn-junctions of graphene published in Advanced Functional Materials.

H. Karakachian, P. Rosenzweig, T. T. N. Nguyen, B. Matta, A. A. Zakharov, R. Yakimova, T. Balasubramanian, Z. Mamiyev, C. Tegenkamp, C. M. Polley, U. Starke, Adv.  Funct. Mater. 2109839 (2022), Periodic nanoarray of graphene pn-junctions on silicon carbide obtained by hydrogen intercalation.

01/01/2022: We are part of the newly established FOR5242

Our group is part of the FOR5242 on epitaxial graphene on SiC.

Tailoring the electronic structure of epitaxial graphene on SiC more

28/12/2021: metal organic layer coposites for high-performance electrocatalytic CO2 reduction accepted for publication in Angewandte Chemie

H. Liu, H. Wang, Y. Song, K. Küster, U. Starke, P. van Aken, E. Klemm, Angew. Chem. Int. Ed. e202117058 (2022). Assembling metal organic layer composites for high-performance electrocatalytic CO2 reduction to formate

11/10/2021: Performance of magnesium-sulfur batteries published in Journal of Power Sources

P. Wang, K. Küster, U. Starke, C. Liang, R. Niewa, M. R. Buchmeiser, J. Power Sources 2021 doi.org/10.1016/j.jpowsour.2021.230604. Performance enhancement of rechargeable magnesium-sulfur batteries based on a sulfurized poly(acrylonitrile) composite and a lithium salt.

10/08/2021: Paper on the intercalation of h-BN on Rh(111) with nanographene flakes published in Advanced Materials Interfaces

K. Küster, Z. Hooshmand, D. P. Rosenblatt, S. Koslowski, D. Le, U. Starke, Talat S. Rahman, K. Kern, U. Schlickum, Adv. Mater. Interfaces 2100766 (2021). Growth of graphene nanoflakes/h-BN heterostructure.

28/07/2021: Ultra-stable cycling of high capacity Sodium-sulfur Batteries published in Batteries & Supercaps

S. Murugan, S. Niesen, J. Kappler, K. Küster, U. Starke, M. R. Buchmeiser, Batteries & Supercaps doi.org/10.1002/batt.202100125. Ultra-stable cycling of high capacity room temperature sodium-sulfur batteries based on sulfurated poly(acrylonitrile).

24/06/2021: Electronic strucutre of the bond disproportinated bismuthate Ag₂BiO₃ published in Phys. Rev. Mater.

M. Ouhda, M. Kim, K. S. Rabinovich, K. Foyevtsova, G. McNally, B. Kilic, K. Küster, R. Green, A. V. Boris, G. Sawatzky, A. P. Schnyder, D. A. Bonn, B. Keimer, H. Takagi, Phys. Rev. Mater. 5, 064202 (2021). Electronic structure of the bond disproportionated bismuthate Ag₂BiO₃.

21/06/2021: Structural transformation of a 2D surface confined network by metal coordination accepted for publication in Chemistry A European Journal

B. D. Baker Cortés, M. Enache, K. Küster, F. Studener, T.-L. Lee, N. Marets, V. Burlach, M. W. Hosseini, M. Stöhr, Chem. Eur. J., 10.1002/chem.202101217. Structural transformation of surface-confined porphyrin networks by addition of Co atoms.

06/05/2021: Topological surface states in epitaxial zigzag graphene nanoribbons published in NanoLetters:

T. T. Nhung Nguyen, N. de Vries, H. Karakachian, M. Gruschwitz, H. Aprojanz, A. A. Zakharov, C. Polley, T. Balasubramanian, U. Starke, C. F. J. Flipse, C. Tegenkamp, Nano Lett. 21, 2876-2882 (2021). Topological surface state in epitaxial zigzag graphene nanoribbons.

11/12/2020: One-dimensional graphene nanoribbons published in Nature Communications.:

H. Karakachian, T. T. Nhung Nguyen, J. Aprojanz, A. A. Zakharov, R. Yakimova, P. Rosenzweig, C. M. Polley, T. Balusubramanian, C. Tegenkamp, S. R. Power, U. Starke, Nat. Commun. 11, 6380 (2020). One-dimensional confinement and width dependent bandgap formation in epitaxial graphene nanoribbons.

This work was highlighted by MAX IV.

19/10/2020: Overdoping of graphene beyond the van Hove singularity published in Phys. Rev. Lett.

P. Rosenzweig, H. Karakachian D. Marchenko, K. Küster, U. Starke; Phys. Rev. Lett. 125, 176403 (2020). Overdoping graphene beyond the van Hove singularity.

This work is highlighted in
Physics Today by H. M. Hill Graphene is doped to an exotic regime
and by M. M. Scherer Graphene Doping Reaches New Levels in Physics 13, 161 (2020)

16/09/2020: Hydrogen-intercalated graphene on SiC as platform for hybrid superconductor devices published in Adv. Quantum Technol.:

F. Paschke, T. Birk, S. Forti, U. Starke, M. Fonin. Adv. Quantum Technol. 200082 (2020). Hydrogen-intercalated graphene on SiC as platform for hybrid superconductor devices.

Instrumentation

Main techniques:

• TOF-SIMS (Time-of-Flight Secondary Ion Mass Spectrometry)
• High resolution PES (Photoelectron Spectroscopy)
• NanoESCA (Electron Spectroscopy for Chemical Analysis)
• AFM (Atomic Force Microscopy)
• Quantitative LEED (Low-Energy Electron Diffraction)

These techniques are supplemented by:

• Optical Profiler.
• Scanning tunneling microscopy (STM) and spectroscopy (STS) in collaboration with University of Konstanz and 4-probe STM in collaboration with University of Chemnitz.
• Synchrotron expertise: angle-resolved photoelectron spectroscopy (ARPES), x-ray photoelectron spectroscopy (XPS), photoemission electron microscopy (PEEM), low-energy electron microscopy (LEEM), x-ray magnetic circular dichroism (XMCD), near edge x-ray absorption fine structure (NEXAFS), high energy grazing incidence x-ray diffraction (GXRD).

Research topics

• Epitaxial graphene on SiC
• Intercalation and doping of epitaxial graphene on SiC
• Structured epitaxial graphene
• 2D materials
• Molecular layers on surfaces