arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2607.00985cond-mat.mtrl-sci
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单个单壁碳纳米管跨SiO$_2$和六方氮化硼生长时的衬底依赖性电输运

Substrate-dependent electrical transport in individual single-walled carbon nanotubes grown across SiO$_2$ and hexagonal boron nitride

Department of Applied Physics, The University of Osaka(大阪大学应用物理系)

Yuanjia Liu, Taiki Inoue, Yoshihiro Kobayashi

AI总结:

通过在同一碳纳米管内直接比较SiO₂和hBN上的沟道,发现hBN衬底能提高碳纳米管的载流子迁移率,而本征小带隙不受影响。

摘要:

碳纳米管(CNTs)的电子输运性质受其周围环境的强烈影响,因此衬底是器件性能的关键因素。本文通过在同一根单壁碳纳米管内直接比较SiO$_2$和六方氮化硼(hBN)上的CNT沟道,展示了hBN上单个单壁CNT的增强载流子输运。这种管内比较消除了管间在手性、直径和缺陷密度上的差异,从而更可靠地评估本征衬底效应。CNT采用气流导向生长法合成,无需转移过程即可获得长且高度对齐的CNT,使单根纳米管能够跨越不同衬底区域。沿单根CNT制备的多沟道场效应晶体管表现出清晰的双极性特性。hBN上的CNT沟道始终表现出比SiO$_2$上更高的场效应迁移率。相反,在电荷中性点附近的温度依赖性输运表现出热激活行为,两种衬底上的激活能相似(15-20 meV),表明CNT的本征小带隙基本不受衬底影响。这些结果直接证明了hBN增强了CNT中的低场载流子输运,并为基于hBN支撑的CNT制备高性能电子器件奠定了基础。

英文摘要:

The electronic transport properties of carbon nanotubes (CNTs) are strongly affected by their surrounding environment, making the underlying substrate a critical factor for device performance. Here, we demonstrate enhanced carrier transport of individual single-walled CNTs on hexagonal boron nitride (hBN) by directly comparing CNT channels on SiO$_2$ and hBN within the same nanotube. This within-tube comparison removes tube-to-tube variability in chirality, diameter, and defect density, allowing the intrinsic substrate effect to be evaluated more reliably. The CNTs were synthesized using gas flow-directed growth, which yields long, well-aligned CNTs without transfer processes, allowing a single nanotube to extend across different substrate regions. Multichannel field-effect transistors fabricated along an individual CNT exhibit clear ambipolar characteristics. CNT channels on hBN consistently exhibit higher field-effect mobility than those on SiO$_2$. In contrast, temperature-dependent transport near the charge neutrality point exhibits thermally activated behavior with similar activation energies (15-20 meV) on both substrates, indicating that the intrinsic small bandgap of CNTs is largely unaffected by the substrate. These results provide direct evidence that hBN enhances low-field carrier transport in CNTs and establish a foundation for the fabrication of high-performance electronics based on hBN-supported CNTs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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