拉伸形变对碳纳米管电子结构的影响

Effect of Stretching on Electronic Structure of Carbon Nanotube

运用第一性原理研究碳纳米管受不同程度的拉伸形变后,对其电子结构及光学性能的影响。结果发现:拉伸后碳纳米管仍是类似管状结构;对碳纳米管不同程度的拉伸,会使碳纳米管表现出不同的导电性能。拉伸长度为49. 2%时,最小禁带宽度变为0,即碳纳米管由直接带隙半导体变为金属性导体;拉伸后碳纳米管在费米能级处的态密度数值均增大,其物理化学活性增强。

This paper,using the first principles,studies the effect of tensile deformation in different degrees on the electronic structure and optical properties of carbon nanotubes.The results show that:carbon nanotubes are still similar tubular structure after stretching;stretching carbon nanotubes in different degrees will make the carbon nanotubes exhibit different conductive properties.When carbon nanotubes are stretched to the length of 49.2%,the minimum width of the gap will become 0 eV,i.e.,the carbon nanotubes are changed from direct band gap semiconductor to metallic conductor;the numerical value of carbon nanotubes state density at the Fermi level increases after stretching,and thus their physical and chemical activity is enhanced.