Tang Shuang
College of Engineering, State University of New York Polytechnic Institute, Albany, NY, 12203, USA.
Sci Rep. 2022 Feb 8;12(1):2060. doi: 10.1038/s41598-022-06078-x.
Since the industrialization of single-phase nanomaterial-based devices is still challenging, intensive research focus has been given to complex materials consisting of multiple nanoscale entities, including networks and matrices of nanowires, nanotubes, nanoribbons, or other large molecules; among these complex materials, networks of carbon nanotubes are a typical example. Detailed knowledge of the energy sensitivity and band gap of electronic transport in such a material system is difficult to detect, despite its importance in electronic, energetic and sensing applications. Here, we propose a new methodology to obtain these quantities using the measured Seebeck coefficient at a certain temperature but different Fermi levels. We discover that the network consisting of semiconducting (11,10)-carbon nanotubes actually exhibits metallic transport at room temperature. It is also interesting to verify that intrananotube ballistic transport is dominant over diffusive scattering by long-range disorder, as well as the quantum hopping resistance at the contact points. The transport asymmetry ratio between the holes and electrons (1.75) is similar to the value observed in pristine graphene samples (1.50).
由于基于单相纳米材料的器件的工业化仍具有挑战性，因此对由多个纳米级实体组成的复杂材料进行了深入研究，这些实体包括纳米线、纳米管、纳米带或其他大分子的网络和矩阵；在这些复杂材料中，碳纳米管网络就是一个典型例子。尽管这种材料系统中的电子输运的能量敏感性和带隙在电子、能量和传感应用中很重要，但对其进行详细了解却很难检测。在这里，我们提出了一种新方法，利用在特定温度但不同费米能级下测量的塞贝克系数来获得这些量。我们发现，由半导体(11,10)-碳纳米管组成的网络在室温下实际上表现出金属输运。同样有趣的是，验证管内弹道输运比长程无序的扩散散射占主导地位，以及接触点处的量子跳跃电阻。空穴与电子之间的输运不对称比(1.75)与原始石墨烯样品中观察到的值(1.50)相似。
