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Chemical and structural inhomogeneity in chemical vapor deposited graphene and molybdenum disulfide based moiré heterostructures

Arti Dangwal Pandey1,*, Lars Buß2, Chithra H. Sharma3,4,5, Pai Zhao4, Thomas F. Keller1,6, Jens Falta7, Robert H. Blick4,8, Jan Ingo Flege2, and Andreas Stierle1,6,†

  • *Contact author: arti.dangwal@desy.de
  • †Contact author: andreas.stierle@desy.de
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Phys. Rev. Materials 10, 104005 – Published 13 October, 2026

DOI: https://doi.org/10.1103/tvv8-j4tg

Abstract

Van der Waals (vdW) heterostructures are attracting enormous attention due to their remarkable physical properties governed by moiré superlattices (MSLs) directly controlled by interlayer twist angles or a lattice mismatch. We investigated surface properties of moiré heterostructures made up of commercially available chemical vapor deposited (CVD) graphene and exfoliated MoS2 layers on silicon oxide, by means of spectroscopy, microscopy, and diffraction. High resolution Auger elemental maps and spectra revealed composition inhomogeneity due to thickness variations in CVD graphene and signatures of oxidation of bare MoS2 surface exposed to the ambient atmosphere. Low-energy electron microscopy and diffraction disclosed local stacking and crystallographic information in the graphene-MoS2 moiré heterostructure, including evidence for small-angle twisted bilayer MSL regions in CVD monolayer graphene. This systematic study helps us to understand the overall configuration of the vdW heterostructures and correlate their structure and performance in transport experiments.

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Phys. Rev. Materials 10, 104005– Published 13 October, 2026
  • Received 5 February 2026
  • Accepted 17 September 2026
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