Dependence of channel thickness on MoTe2 transistor performance with Pt contact on a HfO2 dielectric

Abstract

We investigated the dependence of MoTe2 thickness on it is electrical properties by fabricating several transistors with channel thickness between ∼6 layers and ∼46 layers. The transistor with ∼10-layer channel has the highest hole current, whereas the electron current shows monotonically increase with channel thickness. The measurements of I ds-V ds and temperature dependence show ohmic contact of p-type conduction and Schottky contact of n-type conduction. Thus, the highest hole current is observed in ∼10-layer MoTe2 due to the highest mobility. However, the bandgap of MoTe2 decreases with it is thickness, leading to the reduce of Schottky barrier and the increase of electrons current.