Ambipolar behavior in MoS2 field effect transistors by using catalytic oxidation

Abstract

Modulation of electrical properties in MoS2 flakes is an attractive issue from the point of view of device applications. In this work, we demonstrate that an ambipolar behavior in MoS2 field effect transistors (FETs) can be easily obtained by heating MoS2 flakes under air atmosphere in the presence of cobalt oxide catalyst (MoS2 + O2 → MoOx + SOx). The catalytic oxidation of MoS2 flakes between source-drain electrodes resulted in lots of MoOx nanoparticles (NPs) on MoS2 flakes with thickness reduction from 64 nm to 17 nm. Consequently, N-type behavior of MoS2 FETs was converted into ambipolar transport characteristics by MoOx NPs which inject hole carriers to MoS2 flakes.