Regensburg 2022 – scientific programme

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O: Fachverband Oberflächenphysik

O 81: 2D Materials 4: Heterostructures

O 81.2: Talk

Friday, September 9, 2022, 10:45–11:00, S052

Electronic Structure of Quasi-Freestanding WS₂/MoS₂ Heterostructures — Borna Pielić¹, Dino Novko¹, Iva Šrut Rakić¹, Jiaqi Cai², Marin Petrović¹, Alice Bremerich², Robin Ohmann², Nataša Vujičić¹, Mario Basletić³, Marko Kralj¹, and •Carsten Busse² — ¹Institute of Physics, Zagreb, Croatia — ²Universität Siegen, Germany — ³University of Zagreb, Croatia

Quasi-freestanding heterostructures of semiconductiong two-dimensional materials with sharp interfaces, large built-in electric field, and narrow depletion region widths are proper candidates for the future design of electronic and optoelectronic devices.

Here, we epitaxially grow lateral WS₂-MoS₂ and vertical WS₂/MoS₂ heterostructures on graphene under UHV conditions. By means of scanning tunneling spectroscopy (STS), we examine the electronic structure of monolayer MoS₂, WS₂, and WS₂/MoS₂ vertical heterostructure. Moreover, we investigate band bending in the vicinity of the narrow one-dimensional interface of the WS₂-MoS₂ lateral heterostructure. Density functional theory (DFT) is used for the calculation of the band structures, as well as for the density of states maps at the interfaces. For the WS₂-MoS₂ lateral heterostructure, we find type-II band alignment and determine the corresponding depletion regions, charge densities, and the electric field at the interface.