Chemical Physics and Dynamics of Surfaces – 2D materials – Reactive sputtering of dichalcogenide films

Team

  • Permanent members: Romain Bernard, Hervé Cruguel, Geoffroy Prévot, Sébastien Royer, Nadine Witkowski
  • PhD student: Pedro Lourenço

The objective of the “Lames” project  is to develop a sputtering process compatible with lamellar layers of transition metal dichalcogenides, and particularly sulfides. The fundamental question concerns the understanding of the bombardment by ions on these materials during the growth itself (a plasma obtained by a mixture of Ar/H2S gas is used to sputter the target). The samples synthesized in Uppsala were analyzed at INSP by different techniques. Rutherford Backscattering Spectrometry (RBS), X-ray diffraction (XRD) and atomic force microscopy (AFM), and transmission electron microscopy (TEM) measurements have been used to determine the optimum deposition conditions (partial gas pressures, substrate, temperature) to obtain stoichiometric films with good crystalline quality. Furthermore, we study by tunneling microscopy (STM) and Auger spectroscopy the bombardment of the surface of these transition metal sulfides by low energy rare gas ions. Our first results have allowed us to determine the energy threshold for the production of point defects. Numerical simulations are developed to understand the atomic processes involved and the type of defects created on the surface of these materials.

 

Collaborations

  • Uppsala University  (Sweden)
  • Helmholz Zentrum Berlin (Germany)

 

Funding

  • FLAG-ERA JCT Lames (2017-2021)

 

Transversal topics

  • Confinement quantique et systèmes 2D
  • Croissance – Organisation – Interfaces

 

Publication