Band-Like Transport in High Mobility Unencapsulated Single-Layer MoS2 Transistors

TL;DR

This study demonstrates high mobility, band-like charge transport in unencapsulated single-layer MoS2 transistors, revealing temperature-dependent scattering mechanisms and potential for electronic applications.

Contribution

It provides the first evidence of band-like transport in unencapsulated single-layer MoS2 transistors with high mobility at room temperature.

Findings

High mobility (>60 cm2/Vs) at room temperature.

Charge transport follows a variable range hopping model in the sub-threshold regime.

Mobility decreases with temperature, indicating phonon-limited transport above 100 K.

Abstract

Ultra-thin MoS2 has recently emerged as a promising two-dimensional semiconductor for electronic and optoelectronic applications. Here, we report high mobility (>60 cm2/Vs at room temperature) field-effect transistors that employ unencapsulated single-layer MoS2 on oxidized Si wafers with a low level of extrinsic contamination. While charge transport in the sub-threshold regime is consistent with a variable range hopping model, monotonically decreasing field-effect mobility with increasing temperature suggests band-like transport in the linear regime. At temperatures below 100 K, temperature-independent mobility is limited by Coulomb scattering, whereas, at temperatures above 100 K, phonon-limited mobility decreases as a power law with increasing temperature.