Gate-controlled field emission current from MoS$_2$ nanosheets

TL;DR

This paper demonstrates gate-controlled field emission from MoS$_2$ nanosheets, showing that the back-gate voltage modulates emission current likely through electron affinity changes, enabling a new type of field-effect transistor.

Contribution

It introduces a novel field-effect transistor that uses gate voltage to control field emission current from MoS$_2$ nanosheets, based on electron affinity modulation.

Findings

Gate voltage modulates field emission current.

MoS$_2$ nanosheets exhibit gate-tunable electron affinity.

Field emission can be controlled in high vacuum conditions.

Abstract

Monolayer molybdenum disulfide (MoS$_2$) nanosheets, obtained via chemical vapor deposition onto SiO$_2$/Si substrates, are exploited to fabricate field-effect transistors with n-type conduction, high on/off ratio, steep subthreshold slope and good mobility. The transistor channel conductance increases with the reducing air pressure due to oxygen and water desorption. Local field emission measurements from the edges of the MoS$_2$ nanosheets are performed in high vacuum using a tip-shaped anode. It is demonstrated that the voltage applied to the Si substrate back-gate modulates the field emission current. Such a finding, that we attribute to gate-bias lowering of the MoS$_2$ electron affinity, enables a new field-effect transistor based on field emission.