Study On The Electrical Transport Characteristics Of Several Types Of Carbon Molecule Nanostructures

With the improvement of nanoelectronics and the development of nanoelectronic devices,more and more nanomaterials and structures have been unearthed by scientific researchers.Among them,the most popular carbon nanostructures,such as graphene and carbon nanotubes,have interesting structural forms and excellent electrical properties,which are widely loved by scientific enthusiasts,and they have become the basic materials for the next generation of nanoelectronic devices.With the continuous in-depth exploration of these carbon nanostructures,the strange quantum effects contained in the nanostructures are constantly being explored and applied to the fabrication process of nanoelectronic devices.Based on these phenomena,the research method in this paper mainly combines density functional theory and non-equilibrium Green function to deeply explore and study the electrical transport properties of several types of carbon molecular nanostructures,and find some interesting electron transport in these molecular structures.The phenomenon,after systematic analysis,explains the physical mechanism.In this paper,the all-benzene topology molecular trefoil junction,composite junction[Fe₆2]（PF₆）₁₂ and cyclic carbon nanostructured molecules are used as the main research materials,and the electron transport system is constructed by the method of coupled electrodes,and its electron transport properties are studied.In the all-benzene topology molecular trefoil junction structure,the study found that a negative differential resistance region appeared in the current-voltage curve.The expansion of the trefoil junction structure found that the phenomenon of negative differential resistance still exists.The essential properties of leaf knot molecules.After the physical mechanism analysis,it was found that the origin of the negative differential resistance phenomenon is due to the weakening of the molecular state modulated by the bias voltage,which affects the transmission intrinsic channel and transmission peak accordingly.In the molecular structure of the compound junction[Fe₆2]（PF₆）₁₂,the current-voltage characteristics were studied and found that with the increase of the voltage,the current in some voltage regions of[Fe₆2]（PF₆）₁₂no longer increased,and the"platform"phenomenon appeared.By calculating the transmission spectrum and density of states,it is known that the C atom contributes the most in the whole[Fe₆2]（PF₆）₁₂ system,its p orbital plays a major role,and the molecular-electrode coupling strength is the main reason for the"platform"phenomenon.A negative differential resistance region was found in the molecular system of cyclic carbon nanostructures.After expanding the molecular structure of cyclic carbon nanostructures,it was found that the phenomenon of negative differential resistance still exists.The main reason for this phenomenon is the weakening of the molecular state modulated by the bias voltage,which affects the transmission intrinsic channel and transmission peak.Gd atoms were doped into cyclic carbon nanostructured molecules and coupled with three electrodes,gold probes,single-atom gold chains,and single-atom carbon chains,respectively,and their spin transmission spectra and density of states were studied.The results show that the p orbital of carbon atoms plays an important role in this kind of carbon nanoribbon molecules.The electron transport systems constructed by the three types of carbon molecular structures studied in this paper all have the phenomenon of negative differential resistance,which provides more research and application directions for the research of carbon nanomolecules.