Effect of Processing Parameters on Monolayer MoS2 Prepared by APCVD in a Quasiclosed Crucible

摘要

Chemical vapor deposition is one of the universally acknowledged methods to synthesize two-dimensional transition-metal dichalcogenides with high crystal quality and large size. However, variations in the process parameters directly influence the number of layers and the quality of molybdenum disulfide (MoS2) films. Thus, achieving controllable growth of monolayer MoS2 films is still a challenge. In this study, the immunity of the monolayer nature of MoS2 domains to process parameters was systematically investigated by varying the vaporization/growth temperature, time of sulfur addition, ramp rate, and distance between the precursors and receiving substrate using a quasiclosed crucible in a modified atmospheric-pressure CVD system. The results indicated that incorporating a quasiclosed crucible could facilitate controllable growth of monolayer MoS2 films where the monolayer nature is immune to process parameters. Further, we attempted to elucidate the growth mechanism of monolayer MoS2 films, which will contribute toward precise control over the synthesis of MoS2 and other transition-metal dichalcogenides within a broad processing window.