Study Of Nonlinear Optical Performance And Photoelectric Performance Based On NiPS₃

In recent years,Metal phosphorus trichalcogenides(MPTs)have attracted interest due to their unique electronic structure and energy bands.Studies about MPT have reported on water-splitting to produce hydrogen and oxygen,hydrogen storage,lithium-ion batteries,and ultraviolet photodetectors.By varying the transition metals elements or changing the number of layers,the bandgap range of MPTs is adjusted from 1.3 eV to 3.5 eV,which has broader detection band and higher absorption efficiency than transition metal dichalcogenides(TMDs).MPTs have been predicted to be exfoliated more easily from the bulk due to their lower cleavage energy relative to that of graphite,and a lower formation energy than that of MoS₂.In addition,the strong intra-layer vibrations and structural stability of MPTs have been confirmed with Raman spectroscopy.These studies have shown that MPTs have the advantages of easy preparation,high light absorption,large carrier mobility and high stability,with great research value.Therefore,this paper successfully prepared and studied nickel phosphorus trichalcogenide(NiPS₃),one of the MPTs.The main research work is as follows:1.The detailed preparation method of NiPS₃ material was introduced,including the preparation of bulk MPTs by chemical vapor transport(CVT)method and the preparation of two-dimensional(2D)MPTs by mechanical exfoliation,liquid-phase exfoliation and electrochemical exfoliation.The physical and chemical characterization of the prepared materials were analyzed by different methods,including the optical microscopy,transmission electron microscopy(TEM),atomic force microscopy(AFM),X-ray diffraction(XRD),Raman spectroscopy and X-ray photoelectron spectroscopy(XPS).2.The nonlinear optical performance of the NiPS₃ was studied by using Z-scan measurement system.I found that it has large modulation depth and small saturable strength,verified the saturable absorption performance of NiPS₃ at the wavelength of800 nm and 1030 nm at the first time.Therefore,a saturable absorber based on NiPS₃ nanosheets was prepared,an ytterbium-doped fiber laser based on NiPS₃ nanosheets was constructed,and the mode locking of dissipative soliton was realized.3.For the first time,a photo-electrochemical(PEC)-type detector based on NiPS₃ nanosheets was prepared and its photoelectric performance was tested.The results showed that the PEC-type detector has high photocurrent density,sensitive responsivity,high stability and excellent switching characteristics.