Dissolution-Precipitation Growth of Uniform and Clean Two Dimensional Transition Metal Dichalcogenides

TL;DR

This paper introduces a novel dissolution-precipitation growth method for 2D transition metal dichalcogenides that achieves highly uniform, clean monolayer films on large substrates by controlling metal source diffusion within glass.

Contribution

The paper presents a new DP growth technique that controls metal source supply via diffusion inside glass, enabling uniform and clean 2D TMDCs on large scales, overcoming previous CVD limitations.

Findings

Achieves highly uniform monolayer TMDCs on centimeter-scale substrates.

Eliminates unwanted gas-phase reactions during growth.

Applicable to various TMDCs and their alloys.

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have attracted much interest and shown promise in many applications. However, it is challenging to obtain uniform TMDCs with clean surfaces, because of the difficulties in controlling the way the reactants are supplied to the reaction in the current chemical vapor deposition (CVD) growth process. Here, we report a new growth approach called dissolution-precipitation (DP) growth, where the metal sources are sealed inside glass substrates to control their feeding to the reaction. Noteworthy, the diffusion of metal source inside glass to its surface provides a uniform metal source on the glass surface, and restricts the TMDC growth to only a surface reaction while eliminates unwanted gas-phase reaction. This feature gives rise to highly-uniform monolayer TMDCs with a clean surface on centimeter-scale substrates. The DP growth works well for a large variety of TMDCs and their alloys, providing a solid foundation for the controlled growth of clean TMDCs by the fine control of the metal source.