A WSe2 vertical field emission transistor

• Published in: Nanoscale 2019-01, Vol.11 (4), p.1538-1548
• Main Authors: Antonio Di Bartolomeo, Urban, Francesca, Passacantando, Maurizio, McEvoy, Niall, Peters, Lisanne, Iemmo, Laura, Luongo, Giuseppe, Romeo, Francesco, Giubileo, Filippo
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Chemical vapor deposition; Electric fields; Electron emission; Emissions control; Field emission; High vacuum; Monolayers; Organic chemistry; Quantum tunnelling; Selenides; Semiconductor devices; Silicon dioxide; Silicon substrates; Transistors; Tungsten compounds
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c8nr09068h

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.