High Throughput Characterization of Epitaxially Grown Single-Layer MoS2

TL;DR

This study systematically characterizes the geometrical and optical properties of single-layer MoS2 crystallites grown via chemical vapor deposition, revealing how size influences exciton features and demonstrating a method for assessing sample homogeneity.

Contribution

It provides a high-throughput approach to analyze the optical and geometrical properties of CVD-grown MoS2 crystallites, highlighting size effects on exciton behavior.

Findings

Crystallite size affects B exciton position and broadening.

Orientation does not influence A and B excitons.

Differential reflectance can assess large-area sample homogeneity.

Abstract

The growth of single-layer MoS2 with chemical vapor deposition is an established method that can produce large-area and high quality samples. In this article, we investigate the geometrical and optical properties of hundreds of individual single-layer MoS2 crystallites grown on a highly-polished sapphire substrate. Most of the crystallites are oriented along the terraces of the sapphire substrate and have an area comprised between 10 {\mu}m2 and 60 {\mu}m2. Differential reflectance measurements performed on these crystallites show that the area of the MoS2 crystallites has an influence on the position and broadening of the B exciton while the orientation does not influence the A and B excitons of MoS2. These measurements demonstrate that differential reflectance measurements have the potential to be used to characterize the homogeneity of large area CVD grown samples.