卷曲效应对单壁碳纳米管电子结构的影响

利用计入卷曲效应的单壁碳纳米管(SWCNT)的能量色散关系,计算最低导带的电子速度及有效质量,并与不计入卷曲效应的结果进行了比较.计算结果表明:卷曲效应对电子速度及有效质量的影响与SWCNT的类型密切相关,金属锯齿型SWCNT对卷曲效应最为敏感,其次是扶手椅型SWCNT,最不敏感的是半导体锯齿型SWCNT.由此可以推断,卷曲效应对金属锯齿型SWCNT电子结构及低偏压输运特性影响最大,其次是扶手椅型SWCNT,影响最不明显的是半导体锯齿型SWCNT.这些结果与实验测量及密度泛函理论计算结果完全一致. 关键词： 单壁碳纳米管 卷曲效应 电子速度 电子有效质量

Effects of curvature on the electronic structures of single-walled carbon nanotubes

Based on the energy dispersion relation involving curvature effects for the single-walled carbon nanotube (SWCNT), the electronic velocity and the effective mass of the lowest conduction band for the SWCNT are computed and they are compared with the results without consideration of the curvature effects. The analysis shows that the influences of the curvature effect on the electronic velocity and effective mass depend on type of SWCNT, that is, the metallic zigzag-SWCNT is most sensitive to curvature effect, armchair-SWCNT is second most sensive to curvature effect, and the semiconducting zigzag-SWCNT is poorly sensitive to curvature effect. These findings suggest that curvature effects have the largest effect on the electronic structure and the low-bias transport behaviors of the metallic zigzag-SWCNT,a moderate effect on those of the armchair-SWCNT, and the smallest effect on those of the semiconducting zigzag-SWCNT, which are in good agreement with experimental measurements and the calculated results from the density-functional theory.