Chemical vapor deposition (CVD) is a powerful method employed for high quality monolayer crystal growth of 2D transition metal dichalcogenides with much effort invested toward improving the growth process. Here, we report a novel method for CVD based growth of monolayer molybdenum disulfide (MoS2) by using thermally evaporated thin films of molybdenum trioxide (MoO3) as the molybdenum (Mo) source for co-evaporation. Uniform evaporation rate of the MoO3thin films provides uniform Mo vapor which promotes highly reproducible single crystal growth of MoS2throughout the substrate. These high-quality crystals are as large as 95um and were characterized by scanning electron microscopy, Raman spectroscopy, photoluminescence spectroscopy,atomic force microscopy and transmission electron microscopy. The bottom gated field effect transistors fabricated on as grown single crystals shows n-type transistor behavior with a good on/off ratio of 106 under ambient conditions.Our results presented here addresses the precursor vapor control during the CVD processand is a major step forward toward reproduciblegrowth of MoS2 for future semiconductor device applications.
Published in: "arXiv Material Science".