The Synthesis Of Tungsten Disulfide And The Study Of Its Photoelectric

Tungsten disulfide（WS₂）is one of the representatives in the excessive metal sulfide（TMDCs）,which is widely concerned and studied because of its excellent electrical performance,optical performance and photocatalytic performance.Single layer WS₂ inherits the high mobility of graphene,transparent and flexible features.At the same time,the wide band gap also makes up the defect of the graphene zero band gap.These factors enable WS₂ to have high switching characteristics and have broad development prospects in the field of electronic devices.WS₂ films were prepared by low pressure chemical vapor deposition（CVD）.In the experiment,we explored the influence of the factors such as gas flow,pressure,sulfur source heating temperature and base placement position on the experimental results.We searched for the best suitable conditions and used optical microscopy,Raman technology and atomic force microscopy to characterize the films performance.The results show that the film has good quality,large area and uniform surface.The WS₂ films we have prepared are transferred to the new substrate for the preparation of WS₂ photodetectors.We found that WS₂ devices have better photoelectric response characteristics through testing.We added the band range of the device’s work,extending it to the visible range.The results show that the device has the highest response degree in the 640nm wavelength,which is the most advantageous to the energy saving and reducing consumption of the device,which is more conducive to the observation of the photoelectric response phenomenon.And at 430nm,the quantum efficiency of the device is the highest,which is suitable for the full use of each photon in the beam.We also prepared WS₂-MOSFET with WS₂ film,and the output curve and transfer curve obtained at normal temperature showed good grid voltage control performance.The electrical characteristics of the device under different laser wavelength and different laser power are also studied.The results show that the voltage of the device is decreased with the increase of power,and the source leakage current tends to become saturated faster under the condition of the same source leakage voltage.At different wavelengths,the transfer curve of the device also changes regularly.