Study Of Electric Properties And Band Control For The Blue Phosphorene And Related Structures

The successful preparation of graphene has produced qualitative changes in the study of two-dimensional materials.Graphene has ultra-high carrier mobility and excellent optoelectronic and mechanical properties,which has accelerated the researchers.Explore the pace of two-dimensional material properties,applications and so on.In this paper,we use the first-principles method of density functional theory to study the electronic and optical properties of two-dimensional materials such as blue phosphorus and related structures.Firstly,we studied the calculation of the 1～4 layer blue-phosphorus filmsand its electronic properties.The results show that the blue-phosphorus monolayer is an indirect bandgap semiconductor with a band gap size of 1.93 eV.When we increase the number of layers of the structure and transform the superposition method,the band gap decreases as the number of layers increases.We apply electric fields and stresses to it,and find that both can make the material achieve the opening and closing of the band gap,and the stress can also make the structure of the two or more layers indirectly to the direct band gap semiconductor.These research structures help us to utilize Its electronic properties are designed by strain and electric field controlled on/off nanodevices.In addition,we also calculated the optical properties of the structure.The results show that the material has good absorption intensity in the ultraviolet region and can be used as an alternative material for UV detectors.Our results provide a theoretical basis for the effective regulation of the electronic properties of blue-phosphorus nano-facets.We designed the heterostructures of ZnO monolayer and blue-phosphorus monolayer,and calculated their photoelectric properties,and applied strain and electric field to control their band gaps.The calculation results show that the three heterostructures of the hollow,O and Zn-pattern are indirect bandgap semiconductors with a band gap size of about 1.0 eV.Through the stress and electric field,the band gap of the structure can be regulated.The compressive strain can make the structure have a semiconductor-to-conductor transition,and the tensile strain and electric field can effectively reduce the value of the band gap.The optical property calculation results show that the heterostructure has good absorption intensity in both visible and ultraviolet regions,but the absorption intensity is still in the ultravioletregion.The research results are very important for device design based on blue-phosphorus monolayer structure,and also provide a theoretical basis for device fabrication.In order to study the blue-phosphorus monolayer material more systematically,we dope the blue-phosphorus super-cell with non-metal atoms,calculate its photoelectric properties,and analyze its physical meaning.The results show that some doping atoms induce a slight magnetic property and generate impurity levels near the Fermi surface.The doping atoms also change the optical properties of the intrinsic blue-phosphorus monolayer,resulting in a series of absorption peaks.The material has a very high absorption rate in the ultraviolet region,and our research results can provide a reliable theoretical basis for the study of the doping system of blue phosphorus.Finally,we predicted a two-dimensional phosphorus-based structure GeP.The calculation results show that the material has dynamic stability and still maintains a complete shape at a thermodynamic temperature of 800 K,and the structure has a band gap of ~1.5 eV,external The strain can regulate the band gap opening and closing,and the calculation of optical properties shows that the structure has good absorption in the ultraviolet region.Our calculation results are helpful for the study of high temperature photodetectors,and can provide great theoretical support for device design and preparation.