Band alignment at interfaces of synthetic few-monolayer MoS2 with SiO2 from internal photoemission

I. Shlyakhov, J. Chai, M. Yang, S. J. Wang, V. V. Afanas'Ev, M. Houssa, A. Stesmans

Research output: Journal article publicationJournal articleAcademic researchpeer-review

14 Citations (Scopus)

Abstract

Electron band alignment at interfaces of SiO2 with directly synthesized few-monolayer (ML) thin semiconducting MoS2 films is characterized by using field-dependent internal photoemission of electrons from the valence band of MoS2 into the oxide conduction band. We found that reducing the grown MoS2 film thickness from 3 ML to 1 ML leads to 400 meV downshift of the valence band top edge as referenced to the common energy level of the SiO2 conduction band bottom. Furthermore, comparison of the MoS2 layers grown by a H-free process (sputtering of Mo in sulfur vapor) to films synthesized by sulfurization of metallic Mo in H2S indicates a significant (500 meV) electron barrier increase in the last case. This effect is tentatively ascribed to the formation of an interface dipole due to the interaction of hydrogen with the oxide surface.

Original languageEnglish
Article number026801
JournalAPL Materials
Volume6
Issue number2
DOIs
Publication statusPublished - 1 Feb 2018

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)

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