Towards Intrinsic Charge Transport in Monolayer Molybdenum Disulfide by Defect and Interface Engineering

TL;DR

This study demonstrates that defect and interface engineering via low-temperature thiol chemistry can significantly enhance charge mobility in monolayer MoS2, approaching its intrinsic transport limit for high-performance electronic devices.

Contribution

The paper introduces a novel low-temperature thiol chemistry method to repair sulfur vacancies and improve interfaces in monolayer MoS2, enabling near-intrinsic charge transport.

Findings

Achieved mobility >80 cm² V⁻¹ s⁻¹ in monolayer MoS2 transistors.

Developed a theoretical model to quantify microscopic factors affecting performance.

Reduced charged impurities and traps through defect and interface engineering.

Abstract

Molybdenum disulfide is considered as one of the most promising two-dimensional semiconductors for electronic and optoelectronic device applications. So far, the charge transport in monolayer molybdenum disulfide is dominated by extrinsic factors such as charged impurities, structural defects and traps, leading to much lower mobility than the intrinsic limit. Here, we develop a facile low-temperature thiol chemistry to repair the sulfur vacancies and improve the interface, resulting in significant reduction of the charged impurities and traps. High mobility greater than 80cm2 V-1 s-1 is achieved in backgated monolayer molybdenum disulfide field-effect transistors at room temperature. Furthermore, we develop a theoretical model to quantitatively extract the key microscopic quantities that control the transistor performances, including the density of charged impurities, short-range defects and traps. Our combined experimental and theoretical study provides a clear path towards intrinsic charge transport in two-dimensional dichalcogenides for future high-performance device applications.