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

© 2017 Author(s). Electron band alignment at interfaces of SiO 2 with directly synthesized few-monolayer (ML) thin semiconducting MoS 2 films is characterized by using field-dependent internal photoemission of electrons from the valence band of MoS 2 into the oxide conduction band. We found that reducing the grown MoS 2 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 SiO 2 conduction band bottom. Furthermore, comparison of the MoS 2 layers grown by a H-free process (sputtering of Mo in sulfur vapor) to films synthesized by sulfurization of metallic Mo in H 2 S 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.

Publication year:2018

BOF-keylabel:yes

IOF-keylabel:yes

BOF-publication weight:2

CSS-citation score:1

Authors:International

Authors from:Higher Education

Accessibility:Open