Energy-Level Alignment at Interfaces between Transition-Metal Dichalcogenide Monolayers and Metal Electrodes Studied with Kelvin Probe Force Microscopy.

ABSTRACT: We studied the energy-level alignment at interfaces between various transition-metal dichalcogenide (TMD) monolayers, MoS₂, MoSe₂, WS₂, and WSe₂, and metal electrodes with different work functions (WFs). TMDs were deposited on SiO₂/silicon wafers by chemical vapor deposition and transferred to Al and Au substrates, with significantly different WFs to identify the metal-semiconductor junction behavior: oxide-terminated Al (natural oxidation) and Au (UV-ozone oxidation) with a WF difference of 0.8 eV. Kelvin probe force microscopy was employed for this study, based on which electronic band diagrams for each case were determined. We observed the Fermi-level pinning for MoS₂, while WSe₂/metal junctions behaved according to the Schottky-Mott limit. WS₂ and MoSe₂ exhibited intermediate behavior.

SUBMITTER: Markeev PA 

PROVIDER: S-EPMC8237262 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature