Effect Of Doping On The Electronic And Transport Properties Of Phosphorene And Silicene Nanoribbons

Graphene was fabricated by Geim et al in 2004,and then,a lot of researchers of the world have focused on graphene nanoribbons(GNRs)owing to their out-standing electronic properties.However,zero bandgap character become the short-coming to realize the graphene-based device.Two-dimensional(2D)materials,such as silicene,BN monolayer and transition metal dichalcogenides(Tomes),have become a hot topic in the past few years.For example,phosphorene,it has an inherent,direct and appreciable band gap.It also has a considerable band gap that varies from 0.3 eV to 1.5 e V depending on the number of layers and the strain within the layer.This article mainly studies the effects of doped non-metals and metal atoms on the electronic and transport properties of zigzag phosphorene nanoribbons(ZPNRs)and armchair silicene nanoribbons(ASiNRs).It mainly includes three aspects.(1)In this paper,the first principle method is used to study the effect of heteroatom(boron or nitrogen)doping on the electronic and transport properties of armchair silicene nanoribbons.The calculated results show that the bandgap of armchair silicene nanoribbons(ASiNRs)can be modulated by changing the distance between two doping sites.The ASiNRs appear the semi-metallic property with two boron atoms doping,while the ASiNRs transform from semiconducting to metallic property with two nitrogen atoms doping.It can be found that the bandgaps of ASiNRs are decreasing with the increasing distance between boron atom and nitrogen atom.The transport properties of ASiNRs with B/N codoping are also investigated,the differential conductance appears an oscillatory behavior,which provided a reference for designing silicene nanoribbon electronic devices.(2)The magnetic and electronic properties of the transition metal terminated zigzag phosphorene nanoribbons(ZPNRs)were investigated.It was found that except for the Ni-passivated system,the other systems exhibited magnetic properties to varying degrees,and the magnetic properties varied with the ribbon width.Interestingly,we have found that Fe-passivated ZPNRs exhibit magnetic semiconductors,which indicates that phosphonene is possible in terms of information storage.For the case of Mn-passivated ZPNRs,this system exhibits a magnetic half-metal and The magnetic moment is insensitive to the change of ribbon width.The results show that phosphorene has potential application in spin electronic devices.(3)In order to explore the gas sensing properties of phosphorene,the adsorption of a series of small gas molecules on intrinsic and carbon-doped zigzag phosphorene nanoribbons(C-ZPNRs)were investigated.The calculated results show that NH3,CO2 and O2 gas molecules have relatively larger adsorption energies than other gas molecules,indicating that phosphorene is more sensitive to these gas molecules.For C-ZPNRs configuration,the adsorption energy of NO and NO2 increase and that of other gas molecules decrease.Therefore,doping is an effective method to improve the sensing properties of phosphorene.Interestingly,the adsorption energy of hydrogen is-0.229 eV,which may be suitable for hydrogen storage.