High-Performance Monolayer WS2 Field-effect Transistors on High-k Dielectrics

TL;DR

This paper demonstrates high-performance monolayer WS2 transistors achieved through high-k dielectric and passivation, resulting in record mobility and a transition to metallic conduction, supported by a theoretical transport model.

Contribution

It introduces a novel combination of dielectric and passivation techniques to significantly enhance WS2 transistor mobility and provides a theoretical model for electron transport.

Findings

Record high mobility of 83 cm2/Vs at room temperature

Transition from insulating to metallic charge transport

Development of a theoretical electron transport model

Abstract

The combination of high-quality Al2O3 dielectric and thiol chemistry passivation can effectively reduce the density of interface traps and Coulomb impurities of WS2, leading to a significant improvement of the mobility and a transition of the charge transport from the insulating to the metallic regime. A record high mobility of 83 cm2/Vs (337 cm2/Vs) is reached at room temperature (low temperature) for monolayer WS2. A theoretical model for electron transport is also developed.