Epitaxial Growth of Large Area Single-Crystalline Few-Layer MoS2 with Room Temperature Mobility of 192 cm2V-1s-1

TL;DR

This paper demonstrates a vapor-solid growth method for large-area, single-crystalline few-layer MoS2 films with high room temperature mobility and structural quality, suitable for device applications.

Contribution

It introduces a vapor-solid epitaxial growth process for high-quality, large-area MoS2 films with excellent electrical and structural properties.

Findings

Room temperature mobility of 192 cm2/Vs

Epitaxial growth on sapphire with good structural order

In-plane anisotropy in electron mobility

Abstract

We report on the vapor-solid growth of single crystalline few-layer MoS2 films on (0001)-oriented sapphire with excellent structural and electrical properties over centimeter length scale. High-resolution X-ray diffraction scans indicated that the films had good out-of-plane ordering and epitaxial registry. A carrier density of ~2 x 1011 cm-2 and a room temperature mobility of 192 cm2/Vs were extracted from space-charge limited transport regime in the films. The electron mobility was found to exhibit in-plane anisotropy with a ratio of ~ 1.8. Theoretical estimates of the temperature-dependent electron mobility including optical phonon, acoustic deformation potential and remote ionized impurity scattering were found to satisfactorily match the measured data. The synthesis approach reported here demonstrates the feasibility of device quality few-layer MoS2 films with excellent uniformity and high quality.