Electronic transport modulation on few-layers suspended MoS$_2$ under strain

TL;DR

This study demonstrates how uniaxial tensile strain modulates electronic transport in few-layer suspended MoS$_2$, revealing band gap closing and achieving high gauge factors, with implications for strain-engineered 2D electronic devices.

Contribution

It provides experimental evidence of electronic transport modulation in strained MoS$_2$ and introduces a fabrication method for applying high strains to suspended 2D materials.

Findings

Band gap closing under strain explains IV curve changes.

Maximum gauge factor of 240 achieved in 3-layer MoS$_2$.

Fabrication process enables high strain application to suspended MoS$_2$.

Abstract

The production of new sensors, transducers and electronic components can benefit from the possibility to alter the electronic transport of metal-semicondutor-metal (MSM) devices. 2D materials are extremely appealing for those new technologies. This can determined by several phenomena as piezoelectric effect, piezoresistive effect and modulation of Schottky barrier. In particular, MoS$_2$, among other Transition Metal Dichalcogenides (TMDs), is predicted to show a transition from semiconductor to metal under strain. In this article we present measurements on the modulation of electronic transport on few layer MoS$_2$ suspended ribbons under uniaxial tensile strain. Experimentally observed changes in the two terminal IV curves can be explained in terms of band gap closing in the semiconductor. A maximum gauge factor of 240 is achieved for a 3-layer ribbon. We also report on the fabrication process that allows to apply high strains to suspended MoS$_2$ ribbons, paving the way to future studies on the effect of strain in 2D materials.