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O: Fachverband Oberflächenphysik

O 90: 2D Materials VI: Growth, Structure and Substrate Interaction

O 90.9: Talk

Thursday, March 21, 2024, 17:00–17:15, MA 005

Structural and electronic properties of two-dimensional single-layer HfS₂ on Au(111) — •Monika Schied¹, Paolo Lacovig¹, Marco Bianchi², Philip Hofmann², and Silvano Lizzit¹ — ¹Elettra Sincrotrone Trieste — ²Department of Physics and Astronomy, Aarhus University

HfS₂ is a promising 2D material for low-power semiconductor devices due to its predicted high electron mobility and low contact resistance for n-type carrier transport. For actual applications, layers with excellent structural and electronic properties are needed. However, films with the necessary quality are only available from exfoliation, which is neither scalable nor very reproducible and only few experimental studies on a single-layer (SL) of HfS₂ have been performed so far. In analogy to the growth of high-quality SL transition metal dichalcogenides such as MoS₂ and WS₂ [1,2] we have epitaxially grown an ordered layer of HfS₂ on Au(111). Monitoring the S 2p and Hf 4f core levels in real time by fast X-ray photoelectron spectroscopy allows the fine-tuning of the relevant parameters – such as the dosing rate and temperature – during the growth. The characterization by X-ray photoelectron diffraction, scanning tunnelling microscopy, and low-energy electron diffraction gives insight into the crystal structure of the film grown in this way. In addition, the electronic structure is investigated by angle-resolved photoemission spectroscopy.
[1] Bana, H., et.al., 2D Mater. 5 035012 (2018)

[2] Bignardi, L. et.al., Phys. Rev. Mat. 3, 014003, (2019)

Keywords: Single-layer HfS2; X-ray photoelectron spectroscopy (XPS); X-ray photoelectron diffraction (XPD); Angle-resolved photoelectron diffraction (ARPES); Scanning tunnelling microscopy (STM)