The radius dependence of the electrical conductivity of metallic and semiconducting zigzag carbon nanotubes (CNTs) is theoretically studied. The investigation was done semiclassically by solving the Boltzmann transport equation to derive current density as a function of a homogenous axial dc field and radius of the tube. The analysis was numerically carried out by varying the radius of the materials at a constant temperature. Plots of the normalized current density versus dc field applied along the axis of both materials are presented. We observed that in the case of the metallic zigzag CNTs as the radius increases, the electrical conductivity decreases. On the other hand, in the semiconducting zigzag CNT there was an increase as radius increases. This research shows that thinner metallic zigzag CNTs and thicker semiconducting zigzag CNTs are better conductors of electricity. This investigation therefore offers way of obtaining higher electrical conductivity in both materials without doping. This study therefore shows applications in the development of current conducting nano-devices for scientific systems.

从理论上研究了金属和半导体之字形碳纳米管（CNT）的电导率与半径的关系。通过求解玻尔兹曼输运方程来得出电流密度，该电流密度是同质轴向dc场和管半径的函数，因此可以半经典地进行研究。通过在恒定温度下改变材料的半径来进行数值分析。给出了沿两种材料的轴施加的归一化电流密度与dc场的关系图。我们观察到，在金属之字形CNT的情况下，随着半径的增加，电导率会降低。另一方面，在半导体之字形CNT中，随着半径的增加而增加。这项研究表明，较薄的金属之字形碳纳米管和较厚的半导体之字形碳纳米管是更好的电导体。因此，该研究提供了无需掺杂即可在两种材料中获得更高电导率的方法。因此，这项研究显示了在用于科学系统的电流传导纳米器件的开发中的应用。