Synthesis mechanism of MoS2 layered crystals by chemical vapor deposition using MoO3 and sulfur powders

Monolayer MoS2 layered crystals have attracted significant attention owing to their potential applicability in emerging devices, and chemical vapor deposition (CVD) is the best method so far to obtain monolayer MoS2 single crystals. Although many studies have been published on MoS2 monolayer crystals grown by CVD, there is a lack of understanding of its synthesis pathway. Therefore, in this paper, we studied the mechanism of the synthesis pathway when monolayer MoS2 crystals are synthesized by conventional CVD using MoO3 and sulfur powders. It was found that solid MoO2 produced by the reduction of MoO3 by sulfur plays a very important role in the synthesis of MoS2 layered crystals as an intermediate phase.