Atomically Resolved Structure of Solid/Solid Interfaces


This project targets the determination of the atomically resolved structure and composition across buried interfaces applying transmission electron microscopy (TEM). Mainly Cs-corrected techniques will be used in combination with techniques that exploit inelastic signals. For the different interface formation processes and expected structures, several model systems will be studied, which will be chosen in close cooperation with the groups synthesizing materials.

Polar/non-polar as well as strained/lattice-matched interfaces in semiconductor heterostructures will be a thematic priority. GaP/Si as well as GaAs/Ge is chosen as a nearly lattice-matched system to study the influence of different crystal polarity on the interface formation mechanism. Using interfaces in the (GaIn)(NAsSb) heterostructure system, this knowledge can be correlated with the influence of strain as well as with the influence of metastability of material systems on the interface structure between two inorganic semiconductors. Our knowledge on TEM of radiation-sensitive organic samples will be developed further to image composite structures of layered with organic materials.

Electron scattering and diffraction will be theoretically described with a special focus on the achievable resolution at buried interfaces, taking into account thermally diffuse scattering as well as TEM specimen relaxation, using realistic crystal models, which are calculated by valence force field and density functional theory, as input parameters. The study of different model material systems will allow for a detailed understanding of different electron-matter interaction at interfaces of hybrid materials. From these data a quantitative understanding of the atomic arrangement at interfaces will be derived. This quantified interface structure is a prerequisite for the correlation to growth as well as to the optoelectronic properties of the studied materials.

Project-related publications

  1. J.O. Oelerich, L. Duschek, J. Belz, A. Beyer, S.D. Baranovskii, K. Volz
    STEMsalabim: A high-performance computing cluster friendly code for scanning transmission electron microscopy image simulations of thin specimens
    Ultramicroscopy 177, 91 (2017).
  2. L. Duschek, P. Kükelhan, A. Beyer, S. Firoozabadi, J.O. Oelerich, C. Fuchs, W. Stolz, A. Ballabio, G. Isella, K. Volz
    Composition determination of semiconductor alloys towards atomic accuracy by HAADF-STEM
    Ultramicroscopy 200, 84 (2019).
  3. A. Beyer, L. Duschek, J. Belz, J.O. Oelerich, K. Jandieri, K. Volz
    Influence of surface relaxation of strained layers on atomic resolution ADF imaging
    Ultramicroscopy 181, 8 (2017).
  4. S. Ahmed, M. Bianchini, A. Pokle, M.S. Munde, P. Hartmann, T. Brezesinski, A. Beyer, J. Janek, K. Volz
    Visualization of Light Elements using 4D STEM: The Layered‐to‐Rock Salt Phase Transition in LiNiO2 Cathode Material
    Adv. Energy Mater. 10, 2001026 (2020).
  5. A. Beyer, K. Volz
    Advanced Electron Microscopy for III/V on Silicon Integration
    Adv. Mater. Interfaces 6, 1801951 (2019).
  6. A. Beyer, F.F. Krause, H.L. Robert, S. Firoozabadi, T. Grieb, P. Kükelhan, D. Heimes, M. Schowalter, K. Müller-Caspary, A. Rosenauer, K. Volz
    Influence of plasmon excitations on atomic-resolution quantitative 4D scanning transmission electron microscopy
    Sci. Rep. 10, 17890 (2020).

Prof. Dr. Kerstin VOLZ

Principal InvestigatorPhilipps-Universität MarburgMaterial Science Center (WZMW), Structure & Technology Research LaboratoryPhone: +49-6421 28-22297Project A5 (Volz)Biography

Dr. Andreas Beyer, Researcher

Varun Shankar Chejarla, PhD-student
Saleh Firoozabadi, PhD-student
Johannes Glowatzki, PhD-student
Damien Heines, PhD-student
David Krug, PhD-student
Chenshun Lu, MSc-student

Former Contributors
Dr. María del Rocío Félix Ángel
Dr. Jürgen Belz
Dr. Katharina Gries
Dr. Han Han
Dr. Pirmin Kükelhan
Dr. Manveer Singh Munde
Dr. Jan-Oliver Oelerich