Synthesis And Photoelectric Properties Of Cu₃Se₂ Nanotubes

With the increasing demands and requirements of optoelectronic detection equipment in today's society,the demand for photodetectors has also become larger and larger.The Cu₃Se₂ material is a very important copper chalcogenide semiconductor material.Cu₃Se₂'s energy band structure is very special(direct band gap 2.20 e V,indirect band gap 1.40 e V),and it has great application potential in the field of photodetectors.Moreover,the raw materials used to synthesize this material are abundant,stable,and will not cause damage to the environment,which has great value in practical applications.However,if it is a single Cu₃Se₂ semiconductor material,there will be recombination of photo-generated carriers,which will reduce the performance of the device prepared by Cu₃Se₂.Heterojunction is very effective in suppressing carrier recombination and can also improve device performance.The method used in this paper is a sacrificial template method,the template is Se nanowires,and the material is ascorbic acid,which can prepare high-purity Cu₃Se₂ nanotubes.At the same time,Bi₂S₃nanosheets were grown on the surface of Cu₃Se₂ nanotubes by solution method at room temperature to generate Cu₃Se₂@Bi₂S₃ heterojunction.Electrochemical ultraviolet detectors and ultraviolet-visible light broad-spectrum detectors were prepared from these two materials respectively,and studied Its performance.The specific content of the research:First,the conditions for preparing Se nanowires are room temperature,and the method is a solution method to prepare the template for synthesizing the Cu₃Se₂nanotubes.The reducing agent is ascorbic acid,and the material prepared before annealing is a Se/Cu₂Se composite structure,which is annealed in an atmosphere of Ar gas,and the Ar gas is used as a protective gas.After annealing,a tubular structure of Cu₃Se₂nanomaterials can be obtained.Its characterization uses scanning electron microscope,transmission electron microscope,energy spectrometer,X-ray diffractometer and X-ray photoelectron instrument to analyze its morphology,lattice type and element type.At the same time,the growth mechanism of Cu₃Se₂ nanotubes has also been further explored.The results show that in the whole reaction process,Se nanowires not only act as a template,but also provide Se^2-for the synthesis of Cu₃Se₂.In addition,the copper source the formation process of Cu₃Se₂ is also very important.Then it was assembled with platinum electrodes into a photodetector,and the UV detection performance of Cu₃Se₂ nanotubes was explored under the irradiation of a simulated light source of 325 nm.The experimental results showed that the detector of Cu₃Se₂ vegetation has a very high detection performance for 325 nm light.,With self-supply characteristics.In order to further inhibit the recombination of photogenerated carriers in Cu₃Se₂nanotubes and improve the photoelectric performance of the device,based on the prepared Cu₃Se₂ nanotubes,Bi₂S₃ nanosheets are grown on Cu₃Se₂ through solution reaction at room temperature to form a Cu₃Se₂@Bi₂S₃ nanotube structure,Used to suppress the recombination of photo-generated carriers.The morphology,composition and structure of the prepared Cu₃Se₂@Bi₂S₃ nano-heterojunction were characterized and analyzed by SEM,EDS,TEM and XRD analysis methods.Finally,the Cu₃Se₂@Bi₂S₃ nano heterojunction and platinum electrode are assembled to form a detector,which is irradiated under 325 nm ultraviolet light,530 nm green light and 625nm red light,respectively.The results show that the performance of Cu₃Se₂@Bi₂S₃nano-heterojunction in ultraviolet light is significantly improved compared with that of Cu₃Se₂nanotubes.The response speed is faster,and the photocurrent is larger.In addition,the corresponding spectrum of Cu₃Se₂ nanotubes is also broadened.The UV detector is upgraded to a UV-visible detector.