Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
Center of Materials Science and Optoelectronics Engineering, and School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
Nat Commun. 2023 Mar 25;14(1):1672. doi: 10.1038/s41467-023-37443-7.
Establishing the relationship between the electrical transport properties of single-wall carbon nanotubes (SWCNTs) and their structures is critical for the design of high-performance SWCNT-based electronic and optoelectronic devices. Here, we systematically investigated the effect of the chiral structures of SWCNTs on their electrical transport properties by measuring the performance of thin-film transistors constructed by eleven distinct (n, m) single-chirality SWCNT films. The results show that, even for SWCNTs with the same diameters but different chiral angles, the difference in the on-state current or carrier mobility could reach an order of magnitude. Further analysis indicates that the electrical transport properties of SWCNTs have strong type and family dependence. With increasing chiral angle for the same-family SWCNTs, Type I SWCNTs exhibit increasing on-state current and mobility, while Type II SWCNTs show the reverse trend. The differences in the electrical properties of the same-family SWCNTs with different chiralities can be attributed to their different electronic band structures, which determine the contact barrier between electrodes and SWCNTs, intrinsic resistance and intertube contact resistance. Our present findings provide an important physical basis for performance optimization and application expansion of SWCNT-based devices.
建立单壁碳纳米管（SWCNT）的电子输运性质与其结构之间的关系对于设计高性能基于 SWCNT 的电子和光电子器件至关重要。在这里，我们通过测量由十一种不同（n，m）单手性 SWCNT 薄膜构建的薄膜晶体管的性能，系统地研究了 SWCNT 手性结构对其电子输运性质的影响。结果表明，即使对于具有相同直径但不同手性角的 SWCNTs，导通电流或载流子迁移率的差异也可能达到一个数量级。进一步的分析表明，SWCNTs 的电子输运性质具有强烈的类型和家族依赖性。对于同一家族的 SWCNTs，随着手性角的增加，I 型 SWCNTs 的导通电流和迁移率增加，而 II 型 SWCNTs 则呈现相反的趋势。同一家族不同手性 SWCNTs 的电性能差异可归因于它们不同的电子能带结构，这决定了电极与 SWCNTs 之间的接触势垒、固有电阻和管间接触电阻。我们目前的研究结果为优化基于 SWCNT 的器件的性能和扩展其应用提供了重要的物理基础。
