Speaker
Description
The main aim of this project concerns the epitaxial growth of 2D layered transition-metal dichalcogenides (TMCs) and their structural and electronic characterization by means of in-situ scanning tunneling microscopy (STM), reflection high-energy electron diffraction (RHEED), X-ray photoelectron spectroscopy (XPS) and angle-resolved photoemission spectroscopy (ARPES). Among other 2D TMCs, three candidate compounds, namely HfTe2, ZrTe2 and their alloy HfxZr1-xTe2, are of particular interest since they are shown to possess non-trivial topological properties [1]–[3]. Therefore, epitaxial growth of HfTe2 on three different substrates (InAs, single-layer graphene SLG and Au) using molecular beam epitaxy (MBE) has been performed, with the intention to investigate the challenges related to the growth process, as well as the effect of each substrate on the growth, structure and electronic properties of the grown materials. In that direction, questions related to the growth mode, film uniformity, substrate surface coverage, layer thickness, epitaxial quality, phase/stoichiometry and topological properties were addressed.
References:
[1] S. Aminalragia-Giamini, J. Marquez-Velasco, P. Tsipas, D. Tsoutsou, G. Renaud, and A. Dimoulas, “Molecular beam epitaxy of thin HfTe2 semimetal films,” 2D Mater., 2017.
[2] P. Tsipas et al., “Massless Dirac Fermions in ZrTe2 Semimetal Grown on InAs(111) by van der Waals Epitaxy,” ACS Nano, 2018.
[3] S. Fragkos, P. Tsipas, E. Xenogiannopoulou, Y. Panayiotatos, and A. Dimoulas, “Type-III Dirac fermions in HfxZr1−xTe2 topological semimetal candidate,” J. Appl. Phys., vol. 129, no. 7, p. 075104, 2021.
