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HL: Fachverband Halbleiterphysik

HL 18: 2D Materials and Heterostructures: Emerging Materials and Phenomena

HL 18.5: Talk

Tuesday, March 19, 2024, 10:30–10:45, EW 201

PtSe₂ vdW single-crystal surfaces studied at the atomic scale with ncAFM — •Igor Sokolović^1,2, Saeed Rasouli², Bing Wu³, Zdeněk Sofer³, Aleksandar Matković⁴, Michael Schmid², Ulrike Diebold², and Tibor Grasser¹ — ¹Institute of Microelectronics, TU Wien, Vienna, Austria — ²Institute of Applied Physics, TU Wien, Vienna, Austria — ³Department of Inorganic Chemistry, University of Chemistry and Technology, Prague, Czech Republic — ⁴Chair of Physics, Montanuniversität Leoben, Leoben, Austria

Surfaces of van-der-Waals-bonded (vdW) single-crystal PtSe₂ cleaved in ultrahigh vacuum (UHV) were studied with noncontact atomic force microscopy (ncAFM) at the atomic level. Typical ionic and electronic defects were characterized with single-atom precision: the identification of surface and subsurface defects was achieved by observing the atomic and electronic structure in parallel. The metallic single crystals exhibit a proclivity of the PtSe2 toward different defect types compared to the synthesized trilayer thin films of semiconducting PtSe₂ and other Pt-based TMDs. Cleaved surfaces are representative of the commonly exfoliated flakes so further experiments with in situ deliberate stoichiometry adjustments and the adsorption of gasses will be presented. Additionally, the growth of a CaF₂ dielectric on these surfaces will be demonstrated.

Keywords: PtSe2; Defects; Atomic resolution; Electronic structure; Heterostructures