| The structures of graphene and black phosphorene are relatively unique and both belong to new nanomaterials.According to the current research theory,graphene nanoribbons have better performance in thermal transport.Based on this,This paper deeply study the thermal transport properties of graphene nanoribbons under the action of electric field.Because the structure of black phosphorene and graphene are relatively similar and both have Zigzag and Armchair edges,existing research results show that doping graphene makes it more widely applicable,so this paper explores the use of doping to regulate the properties of black phosphorene.There two research results of this paper:(1)Study the thermoelectric properties of Zigzag graphene nanoribbons under the tuning of electric field;(2)Study the doping of black phosphorene with 3d transition metals,by different atoms and different positions,the results show it has magnetism,which may be used in spin nanodevices.In the first work,we adopt Zigzag graphene nanoribbons with four repeated units as the scattering region which is coupled to two electrodes of graphene to build Spin electronic device.Through first-principles calculations combined with the non-equilibrium Green’s function method,the thermoelectric properties of Zigzag graphene nanoribbons under different electric fields are studied.The results show that the electrical structure and thermal transport properties of graphene nanoribbons can be adjusted by applying a vertical electric field.The Zigzag graphene nanoribbons exhibit a spin-dependent Seebeck effect under a temperature gradient and increase with the width of the Zigzag graphene nanoribbons.The vertical electric field can regulate the process from hole conduction to electron conduction of the device,which provides the possibility for adjusting the heat transfer characteristics of the device through the electric field.In the second work,a single layer of black phosphene is doped with 3d transition metal diatoms,and the properties of black phosphene can be adjusted by the doping of different atoms and different positions.In diatomic doped black phosphene,Ti Mn-BP,Cr Fe-BP,Cr Co-BP,Mn Fe-BP,and Mn Co-BP have bipolar magnetic semiconductor property,and Ti Cr-BP has semi-semiconductor property,and Fe Co-BP have half metal property.In diatomic heterotope-doped black phosphene,Sc Ti-BP,Sc V-BP and Cr Fe-BP have bipolar magnetic semiconductor property,and Ti Mn-BP has Semi-semiconductor property,and Mn Fe-BP has half-metal property.The research results provide a theoretical basis for further exploration to adjust the properties of black phosphorene by doping,thereby generating the properties of bipolar magnetic semiconductors,and promote the 3d transition metal diatomic doping of the same surface and the different surface doped black phosphorene nanoribbons in Thermal transport and applications in spintronic devices. |
