First-principles Investigation Of Doping Effect On Arsenene And Bismuthene

Since graphene was experimentally prepared,two-dimensional semiconductors have gradually developed into a popular direction of study.Among them,arsenene and bismuthene materials have received extensive attention due to their good stability and excellent performance.At present,a large number of theoretical investigations and studies have been conducted on arsenene and bismuthene.However,the research on the electronic structure,magnetic and optical properties of doped arsenene materials is still not comprehensive,and there are few studies on the electronic structure and magnetic properties of doped bismuthene materials.In addition,it is important to adjust the performance of two-dimensional materials in the research by different concentrations doping and applying strain on the doping system,which requires researchers to spend a lot of energy to explore.This article mainly studied the doping characteristics of arsenene and bismuthene under the corresponding effect by using density functional theory,and the doping atoms were transition metals.The calculation results of the Fe-doped arsenene structure show that:(1)The doped structure is a direct band gap semiconductor,introduces a magnetic moment and can achieve room temperature ferromagnetism.In addition,the structure can improve the light absorption in the visible light range.(2)Under 4% biaxial strain,the doped structure exhibits metallic property,under other strains,the systems maintain the spinpolarized semiconductor properties with the direct band gap.Strain effect can change the occupancy state of electrons in arsenene-based materials and also can affect the interaction of Fe and arsenene,so the magnetic moments of the doping structure can increase significantly under 4%,6% and 8% biaxial strains.In addition,the adjustment of the biaxial compression strain can increase the absorption coefficient of visible light.(3)In the arsenene materials,increasing the impurity concentration of Fe atom,the structure can change from the semiconductor state to the metal state,and the magnetic moment is also increased.On the other hand,the increase of the impurity concentration can obviously enhance the light absorption of the arsenene based material in the low energy region.The calculation results of the transition metal V,Cr,Mn and Fe atoms doped bismuthene system show that:(1)The structure doped with V impurity behaves a metallic state,the structure by introducing Cr impurity is a spin-polarized semiconductor,and Mn and Fe-doped structures become half-metallic state.The doped bismuthene system can generate impurity states and introduce local magnetic moments,so all doping systems show magnetism.The V-doped structure exhibit ferromagnetic coupling,but all of the Cr,Mn,and Fe-doped bismuthene structures behave antiferromagnetic state.(2)At the 5.56% doping concentration,the Cr-doped structure can change from semiconductor to half-metal.Under the 12.5% doping concentration,the Mn-doped system can change from half-metallic state to metallic state.In addition,the magnetic moments of the Cr-doped bismuthene system remain stable under different doping concentrations,the magnetic moments of the Mn-doped bismuthene system are relatively stable under low doping concentrations,but the magnetic moments of the V and Fe-doped bismuthene structures can relatively change due to the influence of impurity concentration.