Epitaxial single-crystal growth of transition metal dichalcogenide monolayers via atomic sawtooth Au surface

TL;DR

This paper presents a universal method for the wafer-scale epitaxial growth of transition metal dichalcogenide monolayers using an atomic sawtooth gold surface as a template, enabling high-quality 2D material fabrication.

Contribution

The authors introduce a novel atomic sawtooth gold surface template for the epitaxial growth of various TMdC monolayers, demonstrating a universal and scalable approach.

Findings

Successful growth of several TMdC monolayers on the gold template.

Epitaxial growth driven by anisotropic adsorption energy at atomic steps.

Formation of large-area, single-crystal TMdC films.

Abstract

Growth of two-dimensional van der Waals layered single-crystal (SC) films is highly desired to manifest intrinsic material sciences and unprecedented devices for industrial applications. While wafer-scale SC hexagonal boron nitride film has been successfully grown, an ideal growth platform for diatomic transition metal dichalcogenide (TMdC) film has not been established to date. Here, we report the SC growth of TMdC monolayers in a centimeter scale via atomic sawtooth gold surface as a universal growth template. Atomic tooth-gullet surface is constructed by the one-step solidification of liquid gold, evidenced by transmission-electron-microscopy. Anisotropic adsorption energy of TMdC cluster, confirmed by density-functional calculations, prevails at the periodic atomic-step edge to yield unidirectional epitaxial growth of triangular TMdC grains, eventually forming the SC film, regardless of Miller indices. Growth using atomic sawtooth gold surface as a universal growth template is demonstrated for several TMdC monolayer films, including WS2, WSe2, MoS2, MoSe2/WSe2 heterostructure, and W1-xMoxS2 alloy. Our strategy provides a general avenue for the SC growth of diatomic van der Waals heterostructures in a wafer scale, to further facilitate the applications of TMdCs in post silicon technology.