Energy-Level Alignment at Interfaces between Transition-Metal Dichalcogenide Monolayers and Metal Electrodes Studied with Kelvin Probe Force Microscopy.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).  Kelvin probe force microscopy was employed for this study, based on which electronic band diagrams for each case were determined. 
Kelvin Probe Force Microscopy
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. 
chemical vapor deposition