We have undertaken low-temperature conduction measurements on arc-discharge synthesized, semiconducting multiwalled carbon nanotubes (MWNT). The diameters of these are in the range 2.5–10 nm, corresponding to the sizes just above single-walled carbon nanotubes (SWNT), up to middle-sized MWNTs. The energy gap, inversely related to the diameter, varies strongly in this range, and consequently there is a strong dependence of the transport on tube diameter. Certain transport characteristics are much alike those found in SWNTs, such as the ON-state resistance and Coulomb blockade. However, the transport gap has a more complex behavior than the corresponding one in semiconducting SWNTs, and a number of features, such as negative differential resistance are commonly observed. Different models for the small bias transport behavior are briefly discussed, and we consider especially the possibility of conduction via the second layer.

Graphical abstract

中文翻译：

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半导体多壁碳纳米管的导电性能

我们对电弧放电合成的半导体多壁碳纳米管 (MWNT) 进行了低温传导测量。它们的直径在 2.5-10 nm 范围内，对应于略高于单壁碳纳米管 (SWNT) 的尺寸，直至中等尺寸的 MWNT。与直径成反比的能隙在这个范围内变化很大，因此传输对管直径有很强的依赖性。某些传输特性与 SWNT 中的传输特性非常相似，例如导通状态电阻和库仑阻塞。然而，传输间隙的行为比半导体 SWNT 中的相应行为更复杂，并且通常观察到许多特征，例如负差分电阻。简要讨论了小偏置传输行为的不同模型，

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