Strain Regulation Of Electron Transport Properties Of Low-Dimensional Boron And Nitrogenous Graphene Nanostructures

Nowadays,traditional materials have been unable to meet the pursuit of device miniaturization and high integration.Thanks to the emergence and development of nanotechnology in the past half century,a variety of nanomaterials with unique physical and chemical properties have been continuously produced,which stand out with better electrical properties at the same time of smaller size.Nanomaterials have gradually become the foundation of the next generation of electronic devices in recent years.Based on this,this paper combined density functional theory and non-equilibrium Green’s function to calculate and analyze the electron transport characteristics of low-dimensional boron and nitrogen-based graphene nanomaterials under strain,and at the same time analyzed deeply and clarified the unique physical mechanism behind them according to these characteristics.The main research objects in this paper include Pd₉B₁₆ monomolecular,two-dimensional BeN₄and two-dimensional GaN materials,which aims to realize the regulation of transport properties.In the Pd₉B₁₆ system,it is found that the structure has a very unique negative Poisson’s ratio property in the elastic range.Based on this property,the single molecule is coupled with Au nanowires,Au single-atom chains and C single-atom chains respectively.By adjusting the size of the strain and the location and number of coupling points,the‘metal-semiconductor transition’and‘spin polarized-unpolarized transition’are two transport states.During the study of two-dimensional BeN₄ materials,two-dimensional single-layer BeN₄ nanosheets with Dirac cones in the energy band were cut into different types and widths of nanoribbons according to the edge morphology,showing two conductive mechanisms with different properties of metal and semiconductor.After applying strain to semiconductor nanoribbons,it was found that the band gap of nanoribbons would change linearly with the strain.After analysis,it is concluded that the specific change of the band gap is affected by the degree of atomic p orbital hybridization in the structure.During the study of two-dimensional GaN materials,it is found that the bipolar system with zigzag-type monolayers edge morphology presents spin-polarization related properties,and the polarizability of nanoribbons near the Fermi surface can reach 100%or-100%by constructing specific defects.After exploring the electron transport properties of defective nanoribbons with complete polarization at the Fermi surface under strain,it is concluded that the transmission spectrum of certain configurations can realize complete polarization reversal during the strain process.It is found that the spin up transmission spectrum near the Fermi surface is contributed by the s and p orbitals of Gaatoms.The spin-down transmission spectrum is mainly derived from the p orbital of N atom,which leads to the remarkable spin properties of this configuration.The above three configurations studied in this paper all analyzed the influence of strain on the electrical and spin characteristics of the structures,which provided more exploration and application directions for the subsequent preparation of electronic devices.