Recent Developments in Controlled Vapor‐Phase Growth of 2D Group 6 Transition Metal Dichalcogenides

Abstract

An overview of recent developments in controlled vapor-phase growth of two-dimensional transition metal dichalcogenide (2D TMD) films is presented. Investigations of thin-film formation mechanisms and strategies for realizing 2D TMD films with less-defective large domains are of central importance because single-crystal-like 2D TMDs exhibit the most beneficial electronic and optoelectronic properties. The focus is on the role of the various This article is protected by copyright. All rights reserved. growth parameters, including strategies for efficiently delivering the precursors, the selection and preparation of the substrate surface as a growth assistant, and the introduction of growth promoters (e.g., organic molecules and alkali metal halides) to facilitate the layered growth of (Mo, W)(S, Se, Te) 2 atomic crystals on inert substrates. Critical factors governing the thermodynamic and kinetic factors related to chemical reaction pathways and the growth mechanism are reviewed. With modification of classical nucleation theory, strategies for designing and growing various vertical/lateral TMD-based heterostructures are discussed.Then, several pioneering techniques for facile observation of structural defects in TMDs, which substantially degrade the properties of macro-scale TMDs, are introduced. Technical challenges to be overcome and future research directions in the vapor-phase growth of 2D TMDs for heterojunction devices are discussed in light of recent advances in the field.

Vapor‐phase growth of high‐quality wafer‐scale two‐dimensional materials

“…Another one is to modify the reaction paths by adding catalysts or promoters to reduce the reaction barrier. For example, sodium, potassium, chlorine, and bromine‐containing ionic salts have been demonstrated to effectively promote the growth of TMDs . The third one is to introduce the external energy to predecompose the precursors, such as plasma‐enhanced CVD .…”

“…C. Schematic of three configurations between target substrate and metal precursor: point‐to‐face, horizontal, and face‐to‐face. Reproduced with permission . Copyright 2017, IOP Publishing Ltd. D. Schematic of sulfurization of Pt thin films with a small vent hole quartz tube.…”

“…Reproduced with permission. 7 Copyright 2017, IOP Publishing Ltd. D. Schematic of sulfurization of Pt thin films with a small vent hole quartz tube. Reproduced with permission.…”

“…The past decade has witnessed various breakthroughs in two‐dimensional (2D) materials . Academia and industry have paid tremendous attention and high expectations on 2D materials, as they have broad prospects in various fields owing to their remarkable and tunable physical and chemical properties .…”

“…The past decade has witnessed various breakthroughs in two-dimensional (2D) materials. [1][2][3][4][5][6][7] Academia and industry have paid tremendous attention and high expectations on 2D materials, as they have broad prospects in various fields owing to their remarkable and tunable physical and chemical properties. 8,9 Their practical applications in highperformance electronics and optoelectronics, such as touch screen, radio frequency devices, photovoltaic devices, solar cell, and so on, are hampered by their poor crystalline quality and limited size.…”