Engineering performance of barristors by varying the thickness of WS2

Abstract

We have investigated the performances of barristors with a graphene-tungsten disulfide (WS2) junction by varying the thickness of WS2 and gate oxide. On-current density (JON) and on- and off-current ratio (JON/JOFF) increases, and sub-threshold swing (VSS) decreases with the WS2 thickness. Also, barristors with thicker WS2 required less workfunction shift, to switch the barristors. Therefore, unlike the traditional devices, VSS of barristor with gate dielectric 300 nm was smaller than that of 90 nm, when the former is fabricated with thicker WS2 than the latter. Since materials properties of 2-dimensional semiconductors generally vary with their thickness, the thickness of 2D semiconductors could become a key parameter to engineer the performance of barristors with graphene and the 2D semiconductors. © 2016 Elsevier B.V.