Optimized single-layer MoS2 field-effect transistors by non-covalent functionalisation

TL;DR

This paper demonstrates that non-covalent functionalization of CVD-grown MoS2 with organic molecules enhances the fabrication of high-mobility, fully-encapsulated top-gated FETs, advancing 2D material-based electronics.

Contribution

It introduces a novel non-covalent functionalization method for MoS2 to improve FET fabrication and performance without exposing the channel to polymers.

Findings

High mobility MoS2 FETs achieved with Al2O3 top-gate dielectric.

Functionalization enables fully-encapsulated device fabrication.

Vertical contacts prevent channel exposure to polymers.

Abstract

Field-effect transistors (FETs) with non-covalently functionalised molybdenum disulfide (MoS2) channels grown by chemical vapour deposition (CVD) on SiO2 are reported. The dangling-bond-free surface of MoS2 was functionalised with a perylene bisimide derivative to allow for the deposition of Al2O3 dielectric. This allowed the fabrication of top-gated, fully-encapsulated MoS2 FETs. Furthermore, by the definition of vertical contacts on MoS2, devices, in which the channel area was never exposed to polymers, were fabricated. The MoS2 FETs showed high mobilities for transistors fabricated on SiO2 with Al2O3 as top-gate dielectric. Thus, gate-stack engineering using innovative chemistry is a promising approach for the fabrication of reliable electronic devices based on 2D materials.