| Since graphene was first separated by scholars from the University of Manchester in the United Kingdom,two-dimensional materials have attracted the attention of a wide range of scholars because of their unique electronic structure and physical and chemical properties.Due to the existence of Moore's Law,more scholars tend to find the existence of silicon-based materials,which are one of the most attractive materials due to their unique properties.As the most widely studied transition metal sulfide MoS2,which is called "white graphene" in the academic world,theoretical and experimental studies have shown that single-layer MoS2 is a semiconductor with a direct band gap of about 1.8eV,which makes it a A good complement to the zero-bandgap semi-metal graphene,because the absence of band gap severely limits the practical application of graphene in nanoelectronics.In the work of this paper,we first use the first-principles simulation calculation tool based on density functional theory to study the electronic properties of single-layer MoS2.In order to further optimize and improve the electronic structure of single-layer MoS2,we first explored the defects.The effects on the electronic structure of MoS2 include point defects and line defects.By designing and calculating the electronic structure of the point-defect monolayer MoS2,we find that the vacancy defects of the Mo and S atoms cause a new electronic state to appear in the band,which makes the band gap width narrower and is verified by the transport pattern.This result.Secondly,we designed different line defect structures to explore the influence of line defects on the MoS2 band structure.By calculating the transport patterns of different structures,we can know that the existence of line defects makes the band gap of MoS2 nanoribbon wide,and conductance.The magnitude of the rate will depend to some extent on the direction of transport,and the conductivity along the direction of the armchair will be suppressed more strongly.In the following calculations,we designed and explored the structure and properties of the four-port MoS2 nanoribbon.By calculating the electron transport map of the four-port MoS2 nanobelt,we found that in the cross-type MoS2 nanobelt structure,during the linear conductance transport through the straight channel,there is an insulating tape in the electron transport,however,in the curved channel.The area where the insulating tape is supposed to be present has limited electron transport,and we initially determined that it was affected by the edge state of the nanobelt.Then by operating the width of the nanoribbons,we explored the influencing factors of this finite transport,and the results show that widening the width of the nanoribbon does not enhance the transport intensity,which is in line with our expectations.Next we changed the angle of the nanobelts and the results showed that the change in angle affected the transport state.By calculating the density of states of the four-port MoS2 in different configurations,we demonstrate that the finite transport of the insulating strip in the four-port MoS2 depends on the existence of the edge state of the nanoribbon,and the size of this finite transport is related to the angle of the nanobelt.In the future calculations,we will explore more about the electronic structure of multi-port MoS2 under different bond angles,making single-layer MoS2 more widely used in different scenarios. |
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