Preparation And Electronic And Photoelectric Properties Of WS₂ And ReSe₂ Two Dimensional Materials

Two-dimensional semiconductor materials have been widely used in condensed matter physics,materials science,chemistry,and nanotechnology due to their excellent properties,which have attracted widespread attention.However,the preparation and application of two-dimensional semiconductors are still in the exploratory stage,requiring a large amount of basic research accumulation.In this paper,ReSe₂ was prepared by micromechanical cleavage,and WS₂ was synthesized by chemical vapor deposition.The prepared materials are characterized by atomic force microscopy,Raman,and photoluminescence.To study the electrical and photoelectric properties,the few layers ReSe₂ is used to prepare field effect transistors.The main research contents of the paper include:Chemical vapor deposition is used to Synthesis two-dimensional WS₂ materials on Si/SiO₂ substrates.By adjusting the temperature and growth time,triangular and regular hexagonal single-layer WS₂ films were successfully grown on Si/SiO₂ substrates,which implementation the controllable preparation of two-dimensional WS₂ film.In order to reduce the reaction temperature,the auxiliary reducing substance was introduced to change its reaction mechanism.Atomic force microscope and Raman were used to characterize the grown films.Two-dimensional ReSe₂ films was prepared by micromechanical cleavage,the number of layers of ReSe₂ film was initially identified by optical microscope,and the specific number of layers of ReSe₂ film was confirmed by atomic force microscope.The materials were characterized by Raman and photoluminescence.It was found that the photoluminescence peak of ReSe₂ material was at 1011nm and the band gap was about 1.22eV.The correlation between the optical properties of the material and the number of layers was studied.The field effect transistor which based on micromechanical cleavage ReSe₂ film was prepared,and the corresponding photoelectric characteristics were studied.First,the semiconductor parameter tester is used to test the output characteristic curve and the transfer characteristic curve of the field effect tube,and it is determined that the two-dimensional ReSe₂ crystal is an n-type semiconductor,and its current switching ratio can reach 104,which meets the requirements of modern integrated circuits.Then,Irradiating the transistor with light of different wavelengths in the visible-ultraviolet band.The effects of parameters such as incident light wavelength,power,drain voltage,and gate voltage on the photoelectric response are analyzed,and the internal mechanism of these factors affecting the photoelectric response is explained from the perspective of carrier generation and band regulation.According to the test results:The response time of photodetector based on ReSe₂ reaches 80ms,and the maximum responsivity reached 101A/W,which is 1,000 times of commercial photodetectors.It has broad application prospects in the field of integrated circuits and photodetectors in the future.