Studv On Photoelectric Properties And Band Gap Regulation Of Two-dimensional Antimony Doped With The Same Family

With the successful preparation of graphene,two-dimensionalaterials began to enter people’s field of vision,among which two-dimensional antimony ene attracted people’s attention because of its unique excellent properties and was widely used in various photoelectric devices.According to the literature review,there is no systematic study on the doping and pressurization of two-dimensional antimony at present.In this dissertation,based on the first principles,the electronic and optical properties of few layers of antimony(few layers of Sb)doped with V main group elements are studied,and the adjustment of electronic and optical properties and band gap width of single-layer two-dimensional antimony(singlelayer Sb)under pressure were studied.And the results are analyzed and sorted out.The research in this dissertation is helpful to understand two-dimensional antimony deeply and provide a theoretical basis for its wide application in photoelectric devices.The concrete work is as follows:1.The electronic and optical properties of single-layer Sb doped with V main group elements(Nitrogen(N),phosphorus(P),arsenic(As),bismuth(Bi))were analyzed and studied by using the first-principles calculation method based on density functional theory.Through calculation,it can be seen that the band gap of single layer Sb before and after doping is not closed,and it has semiconductor properties,and the band gap of doped material is reduced.The absorption curve shows that the absorption edge of the doped material is redshifted and the absorption peak is reduced.To sum up,Doping optimizes the photoelectric properties of single-layer antimony,providing a new method for its wide application.2.The electronic and optical properties of a few layers of antimony doped with V main group elements were studied.The calculation results show that the band gap of several layers of Sb doped with V main group elements will gradually decrease until it is closed with the increase of the number of layers,and the material will transition from semiconductor to conductor.According to the dielectric function and absorption curve of each material,with the increase of the number of layers,the dielectric constant of the material increases,the photovoltaic electric field intensity increases,and the absorption in the long wavelength region increases.The results of this study are helpful to understand the photoelectric characteristics of a layer doped with a small amount of Sb and provide theoretical support for its application and research.3.The electronic band structures and optical properties of the monolayer Sb are studied.The impact of pressure on the band-gap and dielectric function of the monolayer Sb is intensively investigated.Its band structure and optical properties are compared with the bulk antimony(bulk Sb).The calculation results show that the bulk Sb is a metal or semi-metal with the band-gap of 0 eV,the monolayer Sb exhibits semiconductor properties with an indirect band-gap of 1.27 eV and its band-gap value is tunable by applying pressure.When the pressure is greater than 3 GPa,the monolayer Sb is changed from a semiconductor to a conductor with a phase transition.These properties of the monolayer Sb demonstrate that it can be used for potential device applications.Its band-gap tunability opens new opportunities for potential applications to nanoelectronic and optoelectronic devices and sensors.