Chemical Vapor Deposition Growth Of Two-dimensional SnS₂ And Studies On Its Device

Two-dimensional materials have been extensively studied due to their unique band structure and excellent mechanical properties.As an important member of two-dimensional layers of metal dichalcogenides family,the two-dimensional?2D?group IV metal chalcogenides?GIVMCs?have been attracting intensive attention because of large band gap,environmental protection,lower cost,novel physical properties and diverse layered crystal structure.There have been many reports based on their electronic and optoelectronic devices.Some performance parameters have exceeded some of the two-dimensional materials currently studied,showing great development potential.However,the growth of monolayer tin disulfide?Sn S₂?remains a great challenge contrasted to transition metal dichalcogenides,which have been studied quite mature.Till date,there have been scant reports on the growth of large-size and monolayer Sn S₂.Here are the main results of this article:?1?We successfully synthesized monolayer Sn S₂ crystal on Si O₂/Si substrates via Na Cl-assisted CVD.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 thickness of 2D Sn S₂ nanosheets,the edge of monolayer Sn S₂ can be as long as 80?m.In addition,we discussed the growing mechanism of the Na Cl-assisted CVD method.?2?Ten layers of SnS₂ grown on a silicon wafer were used as additional materials and electrodes were plated to prepare a photodetector with a back gate structure,test and draw the Output characteristics curve,transfer characteristics curve and response curve under different optical power,and calculate the corresponding parameters.Under 460 nm light illumination and at Vd=50V and Vg=50V,the photoresponsivity and external quantum efficiency of the device can reach about 3.5×10⁵A/W and 9.4×10⁵%with an incident light power of 0.008 m W/cm².Some performance parameters even exceed the traditional TMDCs.Figure 39,table 3,references 69.