Low-cost Millimeter Scale Single-Layer MoS2 Synthesis via Chemical Vapor Deposition

Abstract Two-dimensional (2D) materials are more attractive after the discovery of graphene. Among them, molybdenum disulfide (MoS₂) has been one of the most studied materials due to its striking properties. The monolayer MoS₂ has been mostly deposited by the chemical vapor deposition (CVD) method, and its properties have been tuned by the CVD parameters. However, there is still a need to deposit large-area MoS₂ monolayers more cheaply. In this study, we carried out a controlled synthesis of MoS₂ monolayers with large lateral sizes via the CVD method. The lateral size, number of layers, the distribution of MoS₂ flakes have been tuned with the CVD parameters, which are catalyst amount, growth time, temperature, gas flow rate, sulfur location, and boat type. The synthesized MoS₂ monolayers were analyzed by optical microscope, micro-Raman and photoluminescence (PL) spectroscopy, scanning electron microscope (SEM), and atomic force microscope (AFM). A strong dependency between the lateral sizes and layer numbers of MoS₂ monolayers and CVD deposition parameters has been found. The continuous monolayer film of MoS₂ has been synthesized by using a side-opened quartz. The results show a low-cost way for controllable synthesis of MoS₂ monolayers. The monolayer films can be good candidates for device applications.