Low Temperature Nanoscale Electronic Transport on the MoS_2 surface

TL;DR

This study investigates low-temperature electronic transport on MoS_2 surfaces using two-probe measurements with STM tips, revealing a surface electronic gap and 2D-like resistance behavior at nanoscale separations.

Contribution

First detailed two-probe STM measurement of MoS_2 surface electronic properties at low temperature under ultra-high vacuum.

Findings

MoS_2 surface exhibits a 1.4 eV electronic gap.

Surface resistance shows 2D-like behavior outside the gap.

Surface electronic properties are characterized at nanoscale separations.

Abstract

Two-probe electronic transport measurements on a Molybdenum Disulphide (MoS_2) surface were performed at low temperature (30K) under ultra-high vacuum conditions. Two scanning tunneling microscope tips were precisely positioned in tunneling contact to measure the surface current-voltage characteristics. The separation between the tips is controllably varied and measured using a high resolution scanning electron microscope. The MoS_2 surface shows a surface electronic gap (E_S) of 1.4eV measured at a probe separation of 50nm. Furthermore, the two- probe resistance measured outside the electronic gap shows 2D-like behavior with the two-probe separation.