Study On The Properties Of Graphene-like Layered Structure WS₂

Graphene has attracted extensive attention in recent years because of its unusual electrical, optical, magnetic and mechanical properties. 2D transition metal dichalcogenides(TMDCs) is the material which have a similar structure with the graphene,and therefore, this kind of material has attracted widely interest due to their peticular physical properties and applications in electronics, sensing and photonics. Currently, the researches on the two-dimensional materials of WSe2, MoS2, GaS and GaSe have made some progress. However, as a typical member of 2D TMDCs materials, WS2 thin layers are less studied on their photoelectrical properties. This thesis, based on graphene-like WS2, focuses on the applications of the photoelectric performance.The micro/nanostructured WS2 hexagonal sheets and ribbons were prepared by the chemical vapor deposition with the WS2 amorphous powder and given catalysts. Then the devices were fabricated on the basis of graphene-like layered structure WS2. Then their photoconductive properties were investigated in detail under visible light irradiation. The test results shows that graphene-like layered type structure WS2 have a great on/off ratio under the visible light irradiation with the wavelength of about 465 nm, and moreover the current response to visible light can show repeating cycle.The testing of the thermoelectric performance of WS2 hexagonal sheets shows that the interface states between both ends of the device are different. Moreover, the field effect transistor measurement of singe WS2 micro/nanoribbon shows that it is a p-type conductivity. In addition, the WS2 materials show excellent photoconductivity and photovoltaic effect. The studies of the photoelectric storage performance show also they present good non-volatile memory effect under light illumination.