For the application of single-walled carbon nanotubes (SWNTs) in nanoelectronic devices, techniques to obtain horizontally aligned semiconducting SWNTs (s-SWNTs) with higher densities are still in their infancy. We reported herein a rational approach for the preferential growth of densely packed and well-aligned s-SWNTs arrays using oxygen-deficient TiO₂ nanoparticles as catalysts. Using this approach, a suitable concentration of oxygen vacancies in TiO₂ nanoparticles could form by optimizing the flow rate of hydrogen and carbon sources during the process of SWNT growth, and then horizontally aligned SWNTs with the density of ∼10 tubes/μm and the s-SWNT percentage above 95% were successfully obtained on ST-cut quartz substrates. Theoretical calculations indicated that TiO₂ nanoparticles with a certain concentration of oxygen vacancies have a lower formation energy between s-SWNT than metallic SWNT (m-SWNT), thus realizing the preferential growth of s-SWNT arrays. Furthermore, this method can also be extended to other semiconductor oxide nanoparticles (i.e., ZnO, ZrO₂ and Cr₂O₃) for the selective growth of s-SWNTs, showing clear potential to the future applications in nanoelectronics.

中文翻译：

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缺氧TiO ₂纳米颗粒作为催化剂的密排半导体单壁碳纳米管阵列的生长

对于单壁碳纳米管（SWNT）在纳米电子器件中的应用，获得具有更高密度的水平排列的半导体SWNT（s-SWNT）的技术仍处于起步阶段。我们在此报告了一种合理的方法，用于使用缺氧的TiO ₂纳米粒子作为催化剂，优先生长密集且排列紧密的s-SWNTs阵列。使用这种方法，可以通过在SWNT生长过程中优化氢和碳源的流速，然后以约10管/μm的密度水平排列SWNTs的水平排列，在TiO ₂纳米颗粒中形成合适的氧空位浓度。在ST切割石英基板上成功获得了超过95％的-SWNT百分比。理论计算表明，TiO_2个具有一定氧空位浓度的纳米粒子在s-SWNT之间的形成能比金属的SWNT（m-SWNT）低，因此实现了s-SWNT阵列的优先生长。此外，该方法还可以扩展到其他半导体氧化物纳米颗粒（即ZnO，ZrO ₂和Cr ₂ O ₃）用于s-SWNTs的选择性生长，为纳米电子的未来应用显示出明显的潜力。