We report the first observation of gate-controlled field emission current from a tungsten diselenide (WSe2) monolayer, synthesized by chemical-vapour deposition on 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 {\mu}m^(-1) and exhibit good time stability. Remarkably, the field emission current can be modulated by the back-gate voltage. The first field-emission vertical transistor based on WSe2 monolayer is thus demonstrated and can pave the way to further optimize new WSe2 based devices for use in vacuum electronics.
@article{arxiv.1808.02127,
title = {A WSe2 vertical field emission transistor},
author = {Antonio Di Bartolomeo and Francesca Urban and Maurizio Passacantando and Niall McEvoy and Lisanne Peters and Laura Iemmo and Giuseppe Luongo and Francesco Romeo and Filippo Giubileo},
journal= {arXiv preprint arXiv:1808.02127},
year = {2019}
}