Is Charge-Transfer Doping Possible at the Interfaces of Monolayer VSe2 with MoO3 and K?

Lei Zhang, Xiaoyue He, Kaijian Xing, Wen Zhang, Anton Tadich, Ping Kwan Johnny Wong, Dong Chen Qi, Andrew T.S. Wee

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3 Citations (Scopus)


Being a metallic transition-metal dichalcogenide, monolayer vanadium diselenide (VSe2) exhibits many novel properties, such as charge density waves and magnetism. Its interfaces with other materials can potentially be used in device applications as well as for manipulating its intrinsic properties. Here, we present a scanning tunneling microscopy and synchrotron-based X-ray photoemission spectroscopy study of the surface charge-transfer doping using efficient electron-withdrawing and electron-donating materials, that is, molybdenum trioxide (MoO3) and potassium (K), on the molecular beam epitaxy-grown monolayer VSe2 on highly oriented pyrolytic graphite (HOPG). We demonstrate that monolayer VSe2 is immune to MoO3- and K-doping effects. However, at the monolayer edges where the local chemical reactivity is higher because of Se deficiency, MoO3 is seen to react with VSe2 to form molybdenum dioxide (MoO2) and vanadium dioxide (VO2). Compared to the obvious charge-transfer doping effects of MoO3 and K on HOPG, the electronic structure of monolayer VSe2 is barely perturbed. This is attributed to the large density of states at the Fermi level of monolayer VSe2 carrying the metallic character. This work provides new insights into the chemical and electronic properties of monolayer VSe2, important for future VSe2-based electronic device design.

Original languageEnglish
Pages (from-to)43789-43795
Number of pages7
JournalACS Applied Materials & Interfaces
Issue number46
Publication statusPublished - 20 Nov 2019
Externally publishedYes


  • metallic transition-metal dichalcogenide
  • MoO
  • potassium
  • surface charge transfer doping
  • VSe

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