Journal Article

Judicious Selection of Precursors with Suitable Chemical Valence State for Controlled Growth of Transition Metal Chalcogenides

Xu, Yang, Hong, Yukun, She, Yihong, Zhang, Zhixiang, Pan, Baojun, Lan, Shangui, Wang, Peijian

2023

Overview

Transition metal chalcogenides (TMCs) have attracted wide attentions as a class of promising material for both fundamental investigations and electronic applications due to their atomic thin thickness, dangling bond‐free surface, and excellent electronic properties. Specifically, TMCs show outstanding properties such as good thermal conductivity, robust mechanical properties, and extraordinary electronical characteristics, bestowing them utility in both fundamental research and applications. Recently, the development of post‐Moore electronics based on TMCs calls for their large‐size and single‐crystal growth. However, researchers about synthesis usually focus on controlling several growth parameters (such as growth temperature, flow rate, and time). Herein, it is reported that the chemical valence states of transition metal precursors play an important role in controlling the lateral size and crystal quality for TMCs. The study discusses the valence states‐dependent growth mechanism for WS2 and MoS2 from four factors: evaporation temperature, skipping of reaction steps, atomic binding energy of the precursors, and formation energy. In addition, the as‐grown WS2 and MoS2 nanoflakes exhibit good photoelectric response properties. For EuS, the growth results are obviously different by using EuBr3 and EuBr2 as precursors. The studies provide a unique perspective and also new knowledge to controllably grow large‐size and good crystal quality TMCs. The study reports the chemical valence state of transition metal precursors dependent growth for WS2, MoS2, and EuS. The mechanism can be discussed on four factors: evaporation temperature, skipping of reaction steps, atomic binding energy of the precursors, and formation energy. The lateral size and quality of the as‐grown flakes are all improved. The photoelectric properties of WS2 and MoS2 are comparable with or better than previous reports.

• Publisher: John Wiley & Sons, Inc,Wiley-VCH
• Subject: Chalcogenides / Chemical bonds / chemical valence states / Chemical vapor deposition / chemical vapor deposition (CVD) / Crystal growth / Electronic properties / Free energy / Free surfaces / Grain size / Graphene / Heat of formation / Mechanical properties / Molybdenum disulfide / Photoelectricity / Precursors / Solid lubricants / Spectrum analysis / Temperature / Thermal conductivity / transition metal chalcogenides (TMCs) / transition metal compound precursors / Transition metal compounds / Tungsten disulfide / Valence