扶椅型碳纳米管介电常数和光谱密度泛函研究

First-principles study on the dielectric constant and absorption coefficient of armchair carbon nanotube

为研究扶椅型单壁碳纳米管的介电常数和光谱吸收性质,建立了扶椅型碳纳米管的结构模型,用平面波赝势方法,采用广义梯度近似的密度泛函理论,对扶椅型碳纳米管(5,5)(7,7)(9,9)垂直与平行方向介电常数的虚部以及光谱吸收性质进行了理论计算,计算结果表明:扶椅型碳纳米管为各项异性介质,其光吸收具有偏振性。在合理安排碳纳米管和入射光的角度时,碳纳米管将成为一种理想的可见光吸收材料。

The structure model of armchair carbon nanotubes was built by the method of plan-wave pseudo-potential based on the scheme of generalized gradient approximation in order to investigate the dielectric constant and absorption co- efficient. The dielectric constant and spectrum properties of carbon nanotubes （5,5）, （7, 7）, （9,9） were computed in the perpendicular and parallel directions. The results indicated that armchair carbon nanobube was the anisotropic medium,and the absorption of light was polarized. Armchair carbon nanotube will be the ideal absorption material if it is appropriate placed.