Chemical Vapor Deposition Growth of Large-Area Monolayer MoS2 and Fabrication of Relevant Back-Gated Transistor*.

A closed two-temperature-zone chemical vapor deposition (CVD) furnace was used to grow monolayer molybdenum disulfide (MoS2) by optimizing the temperature and thus the evaporation volume of the Mo precursor. The experimental results show that the Mo precursor temperature has a large effect on the size and shape transformation of the monolayer MoS2, and at a lower temperature of < 760 degrees C, the size of the triangular MoS2 increases with the elevating temperature, while at a higher temperature of > 760 degrees C, the shape starts to change from a triangle to a truncated triangle. A large-area triangular monolayer MoS2 with a side length of 145 mu m is achieved at 760 degrees C. Further, the as-grown monolayer MoS2 is used to fabricate back-gated transistors by means of electron beam lithography to evaluate the electrical properties of MoS2 thin films. The MoS2 transistors with monolayer MoS2 grown at 760 degrees C exhibit a high on/off current ratio of 10(6), a mobility of 1.92 cm(2)/Vs and a subthreshold swing of 194.6 mV/dec, demonstrating the feasible approach of CVD deposition of monolayer MoS2 and the fabrication of transistors on it.