Chemical Vapor Deposition Mediated Phase Engineering for 2D Transition Metal Dichalcogenides: Strategies and Applications

Abstract

2D transition metal dichalcogenides (TMDs) are characterized by the presence of multiple crystal structures or phases, even at the ultrathin limit. Controlling phase transformations, namely, phase engineering, of 2D TMDs is crucial for realizing high‐performance 2D devices by combining phases with distinct physical and chemical properties. As a powerful approach for large‐scale production of high‐quality 2D TMDs, chemical vapor deposition (CVD) offers unique advantages in phase engineering due to its highly controllable synthesis processes. Starting with an introduction of the crystal structures and phase transformations of 2D TMDs, this review summarizes the recent developments in CVD‐mediated phase engineering strategies of TMDs, including control of temperature, precursors, catalysis, atmosphere, composition, and strain during the deposition process. Moreover, the representative applications of CVD‐based phase‐engineered TMDs in the field of transistors, photodetectors, photovoltaic cells, and catalysis are overviewed. Finally, the challenges, expectations of CVD‐based phase engineering, and future development of this versatile technique are discussed.

A Robust Hierarchical MXene/Ni/Aluminosilicate Glass Composite for High‐Performance Microwave Absorption

“…[ 2 , 3 ] Considering the ideal design criteria for the modern MA materials including lightweight, low thickness, and broad absorbing, the 2D materials with a large surface area and a high attenuation capability are very attractive candidate absorbents. [ 4 , 5 ] In particular, the transition metal carbide MXene represented by Ti 3 C 2 T x with a high conductivity and polarization loss has been proved to possess enormous efficiency in microwave shielding. [ 1 , 6 ] However, the extremely large permittivity induced poor impedance matching renders MXene material overwhelmingly reflective feature to the incident microwave, even in the forms of foam or aerogel.…”

Esaki Diode Behavior in Highly Uniform MoS2/Silicon Carbide Heterojunctions

“…[23] In the last years, significant progresses have been achieved in the growth of TMDs by scalable techniques, such as CVD. [24] In particular, the epitaxial growth of semiconducting 2H-MoS 2 on 4H-SiC [25][26][27][28][29] has been recently explored for applications in heterojunction diodes, [25] UV photodetectors, [26] and hydrogen evolution reactions. [29] More specifically, unintentionally doped multilayers of MoS 2 on 4H-SiC have been obtained by one-step CVD at a temperature of 750 °C with vapors from sulfur and MoO 3…”

2D Oxides for Electronics and Optoelectronics

“…CVD is considered as the most promising method for preparing 2D materials, [ 7,8,114 ] which can realize the preparation of high‐quality 2D materials with controllable thickness and excellent reproducibility in a large scale. [ 7,115,116 ] The schematic illustration of CVD is shown in Figure 7 d. The precursors are placed in a quartz tube and evaporated to gas phase under high temperature.…”