Electrical performance of monolayer MoS2transistor with MoS2nanobelt metallic edges as electrodes

Abstract

The contact electrodes have great influence on the performance of monolayer MoS₂devices. In this paper, monolayer MoS₂and MoS₂nanobelts were synthesized on SiO₂/Si substrates via the chemical vapor deposition method. By using wet and dry transfer process, MoS₂nanobelt metallic edges were designed as the source/drain contact electrodes of monolayer MoS₂field effect transistor. The 'nanobelt metallic edges' refers to the top surface of the nanobelt being metallic. Because the base planes of MoS₂nanobelt vertically stand on the substrate, which makes the layer edges form the top surface of the nanobelt. The nonlinearI_ds-V_dscharacteristics of the device indicates that the contact between the monolayer MoS₂and MoS₂metallic edges displays a Schottky-like behavior. The back-gated transfer characteristics indicate that monolayer MoS₂device with MoS₂nanobelt metallic edges as electrodes shows an n-type behavior with a mobility of ∼0.44 cm²V^-1·s^-1, a carrier concentration of ∼7.31 × 10¹¹cm^-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 MoS₂metallic edges in electronic devices.

Keywords: MoS2 nanobelt; contact electrodes; field effect transistor; metallic edges; monolayer MoS2.