Molecular Doping of Multilayer MoS2 Field-effect Transistors: Reduction in Sheet and Contact Resistances

TL;DR

This paper demonstrates that polyethyleneimine (PEI) molecular doping significantly improves the electrical performance of multilayer MoS2 transistors by reducing resistances and increasing current and mobility, showing potential for 2D material applications.

Contribution

First investigation of PEI doping in multilayer MoS2 transistors, showing substantial reductions in sheet and contact resistances and enhanced electrical performance.

Findings

2.6x reduction in sheet resistance

1.2x reduction in contact resistance

70% increase in ON current

Abstract

For the first time, polyethyleneimine (PEI) doping on multilayer MoS2 field-effect transistors are investigated. A 2.6 times reduction in sheet resistance, and 1.2 times reduction in contact resistance have been achieved. The enhanced electrical characteristics are also reflected in a 70% improvement in ON current, and 50% improvement in extrinsic field-effect mobility. The threshold voltage also confirms a negative shift upon the molecular doping. All studies demonstrate the feasibility of PEI molecular doping in MoS2 transistors, and its potential applications in layer-structured semiconducting 2D crystals.