Study On The Structure And Physical Properties Of ? Substituted Doped Silicon Carbide Nanotubes

Silicon carbide(SiC)material is a third-generation wide band gap semiconductor with many superior physical properties and has a wide range of applications in nano-optoelectronic devices.Silicon carbide nanotubes(SiCNTs)are an important low-dimensional semiconductor material.It not only retains the excellent characteristics of SiC crystals,but also exhibits some unique properties of nanotubes,for example,high internal and external surface activity,adjustable electronic structure,good thermal stability,and able to work in extreme conditions.It is widely used in high frequency,high breakdown field strength,high temperature,high thermal conductivity,radiation resistance and other technical fields.Doping can adjust the physical properties of SiCNTs to obtain more valuable semiconductor materials.Based on density functional theory,the effects of group ? elements(N,P,As,Sb)doping on the stability,band structure,electrical and optical properties of SiCNTs have been studied in this paper.The main contents are as follows:Firstly,the basic structure,properties and research contents of SiCNTs and doped SiCNTs are briefly introduced,and the theoretical basis and methods used in this paper are briefly summarized.Secondly,the armchair-type(6,6)SiCNTs and group ? elements replace C and Si SiCNTs models were constructed respectively.Optimize these models and perform firstprinciples calculations on the optimized doped SiCNTs.Then,the theoretical analysis of the calculation results is carried out to obtain the structural stability,energy band and state density distribution of doped SiCNTs.The effects of different elements doping the same site and the same element replacing different sites on the stability and band structure of SiCNTs was compared.Finally,based on first-principles calculations data and semiconductor transport and recombination theory,the effects of different dopants on the transport theory,recombination mechanism and optical properties of SiCNTs were studied by comparison.