Chemical vapor deposition growth of crystal monolayer SnS₂ with NaCl-assistant

As an important member of the two-dimensional layers of metal dichalcogenides family, the two-dimensional (2D) group IV metal chalcogenides (GIVMCs) have been attracting intensive attention. However, the growth of monolayer tin disulfide (SnS₂) remains a great challenge contrasted to transition metal dichalcogenides, which have been studied quite maturely. Till date, there have been scant reports on the growth of large-scale and large-size monolayer SnS₂. Here, we successfully synthesized monolayer SnS₂ crystal on SiO₂/Si substrates via NaCl-assisted CVD and the edge can be as long as 80 μm. Optical microscope, Raman spectroscopy, x-ray diffraction, atomic force microscopy (AFM), and energy-dispersion x-ray (EDX) were performed respectively to investigate the morphology, crystallographic structure, and optical property of the 2D SnS₂ nanosheets. In addition, we discussed the growing mechanism of the NaCl-assisted CVD method.