Quantum tunnelling

Quantum mechanics

Catalysis

Voltage

Engineering

Pure mathematics

Field electron emission

Materials science

Chromatography

Field (mathematics)

Schottky barrier

Transition metal

Biochemistry

Substrate (aquarium)

Diode

Geology

Tungsten diselenide

Oceanography

Transistor

Physics

Nanotechnology

Mathematics

Analytical Chemistry (journal)

Field-effect transistor

Monolayer

Chemistry

Electron

Optoelectronics

Electrical engineering

Engineering physics

Nanoscale

We report the first observation of a gate-controlled field emission current from a tungsten diselenide (WSe2) monolayer, synthesized by chemical-vapour deposition on a SiO2/Si substrate. Ni contacted WSe2 monolayer back-gated transistors, under high vacuum, exhibit n-type conduction and drain-bias dependent transfer characteristics, which are attributed to oxygen/water desorption and drain induced Schottky barrier lowering, respectively. The gate-tuned n-type conduction enables field emission, i.e. the extraction of electrons by quantum tunnelling, even from the flat part of the WSe2 monolayers. Electron emission occurs under an electric field ∼100 V μm-1 and exhibits good time stability. Remarkably, the field emission current can be modulated by the back-gate voltage. The first field-emission vertical transistor based on the WSe2 monolayer is thus demonstrated and can pave the way to further optimize new WSe2 based devices for use in vacuum electronics.

A WSe<sub>2</sub> vertical field emission transistor

A WSe2 vertical field emission transistor

A WSe₂ vertical field emission transistor