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采用基于密度泛函理论(DFT)的第一性原理方法,在广义梯度近似下,对本征单壁锯齿型(6,0)碳化硅纳米管、P或Al掺杂碳化硅纳米管的电子结构和光学性质进行了优化计算.计算结果表明:单壁锯齿型(6,0)碳化硅纳米管为间接带隙半导体,禁带宽度为2.621 eV,价带顶主要由C-2p态电子和Si-3p态电子组成,而导带底则主要由Si-3p态电子决定,且本征碳化硅纳米管的能带间隙和电子性能主要由外层p电子决定.当掺杂P或Al的原子数分数为2.083％时,单壁锯齿型碳化硅纳米管的导带和价带下移,价电子活跃程度提高,导电性能增强,P掺杂或Al掺杂碳化硅纳米管呈现出导体特性.同时静态介电常数增大,在远紫外光波段表现出良好的吸收特性.“,”Under the generalized gradient approximation,the electronic structures and optical properties of the intrinsic single-walled zigzag (6,0) SiC nanotube and P-doped or Al-doped SiC nanotubes were optimally calculated by using the first principles method based on the density function theory (DFT).The calculated results show that the single-walled zigzag (6,0) SiC nanotube is an indirect band-gap semiconductor with the band-gap of 2.621 eV.The top of the valence band is mainly composed of C-2p state electrons and Si-3p state electrons,while the bottom of the conduction band is primarily occupied by the Si-3p state electrons.The band gap and electronic properties of the intrinsic SiC nanotubes are mainly determined by the outer layer p electrons.When the atom number fraction of the doped P or Al is 2.083％,the conduction band and valence band of the single-wall zigzag SiC nanotubes move downward,the valence electron activity increases and the conductivity enhances.The P-doped or Al-doped SiC nanotubes show the conductor characteristics.Moreover,the static dielectric constant of the SiC nanotubes increases,showing good absorption characteristics in far ultraviolet band.