Electrical performance of monolayer MoS2 transistor with MoS2 nanobelt metallic edges as electrodes

Abstract

The contact electrodes have great influence on the performance of monolayer MoS2 devices. In this paper, monolayer MoS2 and MoS2 nanobelts were synthesized on SiO2/Si substrates via the chemical vapor deposition method. By using wet and dry transfer process, MoS2 nanobelt metallic edges were designed as the source/drain contact electrodes of monolayer MoS2 field effect transistor. The ‘nanobelt metallic edges’ refers to the top surface of the nanobelt being metallic. Because the base planes of MoS2 nanobelt vertically stand on the substrate, which makes the layer edges form the top surface of the nanobelt. The nonlinear I ds–V ds characteristics of the device indicates that the contact between the monolayer MoS2 and MoS2 metallic edges displays a Schottky-like behavior. The back-gated transfer characteristics indicate that monolayer MoS2 device with MoS2 nanobelt metallic edges as electrodes shows an n-type behavior with a mobility of ∼0.44 cm2 V−1·s−1, a carrier concentration of ∼7.31 × 1011 cm−2, and an on/off ratio of ∼103. The results enrich the electrode materials of two-dimensional material devices and exhibit potential for future application of MoS2 metallic edges in electronic devices.