论文部分内容阅读
用密度泛函B3LYP/3-21G(d)方法,并利用周期边界条件,研究了n=2—20不同管径的超长(n,n)型单壁碳纳米管的结构、能量、能带结构和能隙.结果表明,管径和能量(或生成焓)都随n有很好的变化规律,并可拟合成很好的解析函数.当n为2和3时,碳纳米管的能隙分别为1.836eV和0.228eV,呈半导体特征,且具有间接带隙;当n=4—20时,能隙介于0.027eV和0.079eV之间,呈较强的金属性,且具有直接带隙.
Using the B3LYP / 3-21G (d) density functional theory and the periodic boundary conditions, the structure, energies and energies of ultra long (n, n) single-walled carbon nanotubes with different diameters of n = 2-20 Band structure and energy gap.The results show that both the tube diameter and the energy (or enthalpy of formation) have a good law of variation with n, and can be fitted into a good analytic function.When n is 2 and 3, the carbon nanotubes Have energy gaps of 1.836eV and 0.228eV, respectively, which are semiconducting features and have an indirect bandgap. When n = 4-20, the energy gap is between 0.027eV and 0.079eV, exhibiting a strong metallic property and having Direct band gap.