Tuning Of The Electronic And Transport Properties Based On Black Phosphorene Nanoribbons

As new low-dimensional materials,black phosphorene and its nanoribbons have some peculiar physical properties due to their scale reaching the nanometer level,such as excellent electrical,optical and mechanical properties.However,the practical application of black phosphorene nanoribbon in spintronic devices has yet to be explored,so how to regulate their spin transport efficiently has become the core problem of our research.At the same time,we can adjust their electronic and transport properties by doping,applied stress or edge passivation.This means that the study of black phosphorene nanoribbons is of great significance for the preparation of nextgeneration nano-electronic devices.The main content of this study is to tune the electronic and transport properties of black phosphorene nanoribbons,thereby broadening their applications in electronic devices.We mainly take two ways to tune:(1)Based on the substitution of vanadium atoms for phosphorus atoms at different positions in the zigzag phosphorene nanoribbons,the electronic structure and spin transport properties of the zigzag phosphorene nanoribbons were studied by combining density functional theory and non-equilibrium Green's function methods.Analyzing their energy band structures and density of states,it is found that doping vanadium atoms in different positions of zigzag phosphorene nanoribbons can make them change from non-magnetic metal to magnetic metal or semi-metal,which is due to the difference between different electron orbitals in the crystal field caused by hybridization.The transport properties were analyzed in detail from the perspectives of I-V characteristic curves,transport spectra and molecular energy levels.The results show that a strong negative differential resistance effect is observed in all investigated devices,and an almost 100% spin filtering effect is found at low bias voltages.V-doped zigzag phosphorene nanoribbons have potential applications in multifunctional spintronic devices.(2)First-principles simulations of the electronic and transport properties of zigzag black phosphorene nanoribbons were carried out by changing the edge passivation.Different types of edge passivation were found to transform zigzag phosphorene nanoribbons from nonmagnetic metals to magnetic semiconductors.Furthermore,devices composed of V-doped zigzag phosphorene nanoribbons composed of different types of edge passivation were designed and their spin transport properties were investigated.The results show that the V-doped zigzag phosphorene nanoribbons passivated with hydrogen or halogen elements have a dual-spin filtering effect with a wide range of bias voltages.At the same time,these structures are also accompanied by a negative differential resistance effect.These special spin transport properties are further analyzed and explained by the calculated transport spectra and local density of states.When the V-doped phosphorene nanoribbons are passivated by sulfur or oxygen atoms,the magnitude of the current changes significantly.This study provides theoretical support for regulating the electron transport properties of zigzag phosphorene nanoribbons.