A First-principles Study On Passivated Phosphorene Nanoribbons

With the rapid development of information technology and explosive growth of information,new requirements for information transmission and storage devices are put forward.So it's imperative to update and develop novel kinds of electronic devices.Scientists and manufacturers all expect excellent materials to make electronic devices,especially semiconductor materials.Since successful synthesis of graphene in 2004,two-dimensional?2D?materials become new stars in the nanomaterial families.Since then,members of two-dimensional materials have been expanded,silicene,germanene,BN monolayer,transition metal sulfides,all of which play an irreplaceable role with excellent performance in materials.Recently,scientists discovered another excellent monolayer—semiconducting phosphorene.Scientists have discovered nine kinds of phosphorene allotropes,but black and blue phosphorenes are most stable and excellent.Compared with graphene without band gap,the phosphorene with band gap can switch the logic circuit on or off.The black phosphorene possessed high carrier mobility,while blue phosphorus has a wide band gap.These excellent properties make the black phosphorene and blue phosphorene become a hot topic.However,the inherent properties of materials usually fail to meet all needs,and we hope that the materials could be"tailored"according to our needs.The modulations played an important role in changing the materials properties.The common modulations methods include shear,modification,applying electric field,applying external magnetic field,strain,doping,substrate modulation and so on.With the developments of computational computer technology,quantum chemistry,computational chemistry is able to predictthe materials properties,which guides the experiments and make computational chemistry an indispensable tool in chemistry.We performed first-principles study on Fe,Co and Ni terminated zigzag phosphorene nanoribbons?ZPNRs?with different width.Magnetic edges are observed for Fe and Co terminated ZPNRs while Ni terminated phosphorene nanoribbons?Ni-ZPNRs?are nonmagnetic.Interestingly,magnetism could be induced in Ni-ZPNRs by external electric fields,and the distribution of the magnetic moments could be tuned by the direction of electric fields.Furthermore,Fe-ZPNRs and Co-ZPNRs exhibit semimetallic and metallic characteristic,respectively,while Ni-ZPNRs are mainly semiconductors with band gaps generally increased monotonously with the increase of the nanoribbon width.These fascinating properties of ion group atoms terminated ZPNRs indicate great potential applications in future spintronics,optoelectronics and information technologies.We also studied the modulation effect of non-metal functional groups?H,F,Cl,O,-NO₂?on armchair blue phosphorene nanoribbons?H/F/Cl/O/NO₂-ABNRs?and zigzag blue phosphorene nanoribbons?H/F/Cl/O/NO₂-ZBNRs?with different width.In addition,we also studied the structures of blue phosphorene nanoribbons terminatd with H/O atoms under electric fields.The results showed that different functional groups can modulate the band structure of blue phosphorene nanoribbons,which indicated that termination on edges is an effective modulation method.However,the blue phosphorene nanoribbons terminated with non-metal functional groups cannot transform semiconductors to conductors,which indicated that the modulation effect of non-metal functional groups on band structure is not good as 3d transitional metals.The electric fields have effect on blue nanoribbons terminated with H/O.Especially for H-ABNRs,the band gap are reduced significantly under electric fields.