Probing the Growth Improvement of Large-Size High Quality Monolayer MoS₂ by APCVD.

Tao Han,Shupeng Chen,Shulong Wang,Xiaoli Yang,Wei Li,Hongxia Liu

doi:10.3390/nano9030433

Abstract

Two-dimensional transition metal dichalcogenides (TMDs) have attracted attention from researchers in recent years. Monolayer molybdenum disulfide (MoS2) is the direct band gap two-dimensional crystal with excellent physical and electrical properties. Monolayer MoS2 can effectively compensate for the lack of band gap of graphene in the field of nano-electronic devices, which is widely used in catalysis, transistors, optoelectronic devices, and integrated circuits. Therefore, it is critical to obtain high-quality, large size monolayer MoS2. The large-area uniform high-quality monolayer MoS2 is successfully grown on an SiO2/Si substrate with oxygen plasma treatment and graphene quantum dot solution by atmospheric pressure chemical vapor deposition (APCVD) in this paper. In addition, the effects of substrate processing conditions, such as oxygen plasma treatment time, power, and dosage of graphene quantum dot solution on growth quality and the area of the monolayer of MoS2, are studied systematically, which would contribute to the preparation of large-area high-quality monolayer MoS2. Analysis and characterization of monolayer MoS2 are carried out by Optical Microscopy, AFM, XPS, Raman, and Photoluminescence Spectroscopy. The results show that monolayer MoS2 is a large-area, uniform, and triangular with a side length of 200 μm, and it is very effective to treat the SiO2/Si substrate by oxygen plasma and graphene quantum dot solution, which would help the fabrication of optoelectronic devices.

Highlights

Molybdenum disulfide (MoS2) has attracted attention from researchers in recent years because of its excellent physical properties
MoS2 is a two-dimensional transition metal dichalcogenides (TMDs) with an adjustable band gap structure in which atoms in layers are bonded by covalent bond interaction, whereas interlayer atoms are coupled by weak van der Waals forces [5,6]
The large-area uniform triangle monolayer MoS2 with a side length of 200 μm is prepared on an SiO2/Si substrate by atmospheric pressure chemical vapor deposition (APCVD) without vacuum treatment, which can provide materials for the photovoltaic devices effectively [25]

Summary

Introduction

Molybdenum disulfide (MoS2) has attracted attention from researchers in recent years because of its excellent physical properties. Due to the existence of a direct band gap, field effect transistors based on monolayer MoS2 have higher current switching ratio and electron mobility at room temperature [10,11]. It can be used in phototransistors [12], logic circuits [13], secondary batteries, and photo catalysis [14]. The large-area uniform triangle monolayer MoS2 with a side length of 200 μm is prepared on an SiO2/Si substrate by atmospheric pressure chemical vapor deposition (APCVD) without vacuum treatment, which can provide materials for the photovoltaic devices effectively [25]. It is concluded that it is possible to obtain the large-area high-quality monolayer MoS2 by treating SiO2/Si substrate with oxygen plasma and graphene quantum dot solution, which would contribute to the preparation of photovoltaic device

Methods

Conclusions