Controlled growth of high spatial uniformity of monolayer single crystal MoS2

MoS 2 nano-films have attracted extensive interest from scientists owing to its unique material properties with adjustable bandgap structure and broad application prospects in electronic and optoelectronic devices. Herein, we report a chemical vapor deposition method based on adjusting the relative position of the molybdenum source and SiO 2 /Si substrates to control MoO 3 concentration adsorbed on the surface of substrate to achieve the controlled growth of monolayer single crystal MoS 2 with spatial uniformity and low nucleation density. Moreover, optical microscopy, Raman, photoluminescence, atomic force microscopy and transmission electron microscope were employed to characterize the uniformity and crystal quality of the grown monolayer MoS 2 . The measurement results show that the triangle side length of a single MoS 2 film can reach 110 μm. And the I-V switching ratio of the back-gate field effect transistors based on growing MoS 2 is 6.3 × 10 8 , which is equivalent or slightly higher than that of other CVD-grown samples. Besides, growth mechanism of MoS 2 was further investigated, combining the substrate position with concentration of MoO 3 deposited on the surface of substrate. This work is of great benefit to the controlled growth of other two-dimensional materials and uniform performance of multiple electronic array devices.