The Stability And Electronic Properties Of A New Zigzag Silicene Nanoribbons And Silicon Nanotubes

Quasi-one-dimensional nanomaterial have been widely concerned due to their potential applications in nanotechnology.With the rapid development of integrated circuits,silicon played an important role.It was believed that silicon will become the cornerstone of the information age.The structure of a new zigzag silicene nanoribbons?ZSiNRs?with periodically embedded with four-and eight-membered rings was calculated by using density functional theory?DFT?.The influence of different widths and edge shapes on the electronic property for the new ZSiNRs and their electronic property with vacancy defects were studied.In addition,the stability and electronic properties of new zigzag silicon nanotubes?ZSiNTs?were also calculated.The main contents of the full text are as follows:The first chapter introduced the definition,development classification and future research directions.And then the graphene was briefly introduced and next to it,silicene,one of the graphene-like was introduced.Finally,the experimental and theoretical research status of the silicene nanoribbons?SiNRs?and silicon nanotubes?SiNTs?was emphatically introduced.The second chapter introduced the theory involved in the calculation,mainly for DFT.In addition,a brief introduction of the Gaussian 03 calculation packages required for theoretical calculations and the calculation method of this article was given.The third chapter described the research content of this article in detail.First of all,based on the newly synthesized graphene-like nanoribbons,the corresponding H-terminated ZSiNRs were constructed.Then the various width for the structures of Z₁-SiNRs and Z₂-SiNRs were optimized,which the variation of nanoribbon width was increased layer by layer.The results showed that with the increase of width by layer,the band gap of Z₁-SiNRs gradually decreased and disappeared at₁m?8,Z₁-SiNRs was gradually changed from semiconductor to metal properties.The overall band gap of Z₂-SiNRs showed a tendency of decreasing fluctuation,Z₂-SiNRs also transformed from semiconductor to metal properties.The average binding energy was increased by fluctuation,there was a concussion repetition interval of every two layers for Z₁-SiNRs and every five layers for Z₂-SiNRs,which was the reappearance of the unit cell.The vacancy defects restructured the structure of Z₂-SiNR?21,3?,increased the band gap and energies significantly,but the position of the vacancy defects could not change the structure and electronic properties.The vacancy defects was easier to form in the edge area for Z₂-SiNRs.Chapter 4 described the stability and electronic properties of the new ZSiNTs.The results showed that the new ZSiNTs behaved a corrugated surface,their energy stability does not depend on the diameter of the ZSiNTs.Most of the?g,0?-type ZSiNTs were semiconducting,while the?0,k?-type ZSiNTs gradually changed from semiconducting to metallic as the nanotubes diameter increases.