High-Mobility and High-Optical Quality Atomically Thin WS2

TL;DR

This paper presents a novel synthesis method for atomically thin WS2 with high optical and electronic quality, achieving record mobility and sharp photoluminescence, advancing the potential for technological applications.

Contribution

The study introduces a molecular precursor-based growth technique for WS2, resulting in superior material quality and scalable, deterministic layer control compared to previous methods.

Findings

Record room temperature charge carrier mobility of 52 cm2/Vs

Ultra-sharp photoluminescence linewidth of 36 meV

Scalable synthesis with deterministic layer control

Abstract

The rise of atomically thin materials has the potential to enable a paradigm shift in modern technologies by introducing multi-functional materials in the semiconductor industry. To date the growth of high quality atomically thin semiconductors (e.g. WS2) is one of the most pressing challenges to unleash the potential of these materials and the growth of mono- or bi-layers with high crystal quality is yet to see its full realization. Here, we show that the novel use of molecular precursors in the controlled synthesis of mono- and bi-layer WS2 leads to superior material quality compared to the widely used topotactic transformation of WO3-based precursors. Record high room temperature charge carrier mobility up to 52 cm2/Vs and ultra-sharp photoluminescence linewidth of just 36 meV over submillimeter areas demonstrate that the quality of this material supersedes also that of naturally occurring materials. By exploiting surface diffusion kinetics of W and S species adsorbed onto a substrate, a deterministic layer thickness control has also been achieved promoting the design of scalable synthesis routes.