Abstract

We employed an ultra-high vacuum exfoliation method to prepare large-area monolayers of WS₂ and WSe₂ on metallic substrates (Au, Ag). Low-energy electron diffraction was used to investigate rotational alignment, optical microscopy assessed exfoliation yield and flake size, atomic force microscopy verified thickness, and X-ray photoelectron spectroscopy and X-ray diffraction were used to examine interfacial chemistry and substrate integrity. The results show that WSe₂ consistently yields larger, less fragmented monolayers than WS2, and that the exfoliation process does not induce covalent bonding or noticeable substrate deformation.

Abstract

We employed an ultra-high vacuum exfoliation method to prepare large-area monolayers of WS₂ and WSe₂ on metallic substrates (Au, Ag). Low-energy electron diffraction was used to investigate rotational alignment, optical microscopy assessed exfoliation yield and flake size, atomic force microscopy verified thickness, and X-ray photoelectron spectroscopy and X-ray diffraction were used to examine interfacial chemistry and substrate integrity. The results show that WSe₂ consistently yields larger, less fragmented monolayers than WS2, and that the exfoliation process does not induce covalent bonding or noticeable substrate deformation.

Abstract

We employed an ultra-high vacuum exfoliation method to prepare large-area monolayers of WS₂ and WSe₂ on metallic substrates (Au, Ag). Low-energy electron diffraction was used to investigate rotational alignment, optical microscopy assessed exfoliation yield and flake size, atomic force microscopy verified thickness, and X-ray photoelectron spectroscopy and X-ray diffraction were used to examine interfacial chemistry and substrate integrity. The results show that WSe₂ consistently yields larger, less fragmented monolayers than WS2, and that the exfoliation process does not induce covalent bonding or noticeable substrate deformation.

Abstract

We employed an ultra-high vacuum exfoliation method to prepare large-area monolayers of WS₂ and WSe₂ on metallic substrates (Au, Ag). Low-energy electron diffraction was used to investigate rotational alignment, optical microscopy assessed exfoliation yield and flake size, atomic force microscopy verified thickness, and X-ray photoelectron spectroscopy and X-ray diffraction were used to examine interfacial chemistry and substrate integrity. The results show that WSe₂ consistently yields larger, less fragmented monolayers than WS2, and that the exfoliation process does not induce covalent bonding or noticeable substrate deformation.