Electronic transport properties of two-dimensional tetragonal zinc chalcogenides.

Abstract

The electronic transport properties of two-dimensional (2D) tetragonal ZnX (X = S, Se) monolayers have been studied using density functional theory (DFT) and non-equilibrium Green's function (NEGF) methods. The gate voltage (a 5 V in particular) generally enhances the transport performance of the monolayers, which is ca. three times that without the gate voltage. It is shown that the transport properties of the Janus Zn2SeS monolayer may show a relatively good trend among the ZnX monolayers, and the Zn2SeS monolayer has the highest sensitivity to gate-voltage regulation. We also investigate the photocurrent of ZnX monolayers under linearly polarized light irradiation in the visible and near-ultraviolet regions, and the ZnS monolayer processes a maximum value of 15 a02 per photon in the near-ultraviolet region. The excellent electronic transport properties make environmentally friendly tetragonal ZnX monolayers promising for utilization in various electronic and optoelectronic devices.