High-performance partially aligned semiconductive single-walled carbon nanotube transistors achieved with a parallel technique.
High-performance partially aligned semiconductive single-walled carbon nanotube transistors achieved with a parallel technique.
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DOI：
10.1002/smll.201203178
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发表时间：
2013-09
期刊：
影响因子：
13.3
通讯作者：
Yilei Wang;S. K. Pillai;M. Chan-Park
中科院分区：
文献类型：
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作者：
Yilei Wang;S. K. Pillai;M. Chan-Park
单壁碳纳米管（SWNT）被广泛认为是下一代印刷电子晶体管材料的有力竞争者。然而，大规模基于解决方案的单壁碳纳米管并行组装以获得高性能晶体管器件具有挑战性。 SWNT 具有各向异性特性，尽管理论上预测纳米管的部分排列可以实现最佳晶体管器件性能，但迄今为止还没有基于并行解决方案的技术可以实现这一点。据报道，一种基于解决方案的新颖技术，即浸入兼振动方法，可使用半导体（99％富集）SWNT（s-SWNT）实现部分对齐的SWNT网络。通过将氨基硅烷处理的晶片浸入放置在旋转振荡器上的纳米管溶液中，沉积过程中纳米管溶液在晶片表面上的重复流动使纳米管朝向流体流动方向。通过调节溶液中纳米管的浓度，可以控制部分排列网络的纳米管密度；观察到的线密度范围为 5 至 45 SWNT/μm。通过控制线性 SWNT 密度和沟道长度，基于 SWNT 的最佳场效应晶体管器件实现了出色的性能指标（开/关比约为 3.2 × 10(4)，迁移率为 46.5 cm(2) /Vs）。原子力显微镜显示，部分排列在 20 × 20 mm(2) 的区域内是均匀的，并证实纳米管的取向主要沿着流体流动方向，具有狭窄的取向分散特征，除了最致密的薄膜外，所有薄膜的半峰全宽 (FWHM) 均小于 15°，即 35°。这种并行过程可大规模应用，并利用了单壁碳纳米管的各向异性特性，为印刷、柔性和大面积电子产品中单壁碳纳米管的工业采用提供了一条可行的道路。
Single-walled carbon nanotubes (SWNTs) are widely thought to be a strong contender for next-generation printed electronic transistor materials. However, large-scale solution-based parallel assembly of SWNTs to obtain high-performance transistor devices is challenging. SWNTs have anisotropic properties and, although partial alignment of the nanotubes has been theoretically predicted to achieve optimum transistor device performance, thus far no parallel solution-based technique can achieve this. Herein a novel solution-based technique, the immersion-cum-shake method, is reported to achieve partially aligned SWNT networks using semiconductive (99% enriched) SWNTs (s-SWNTs). By immersing an aminosilane-treated wafer into a solution of nanotubes placed on a rotary shaker, the repetitive flow of the nanotube solution over the wafer surface during the deposition process orients the nanotubes toward the fluid flow direction. By adjusting the nanotube concentration in the solution, the nanotube density of the partially aligned network can be controlled; linear densities ranging from 5 to 45 SWNTs/μm are observed. Through control of the linear SWNT density and channel length, the optimum SWNT-based field-effect transistor devices achieve outstanding performance metrics (with an on/off ratio of ~3.2 × 10(4) and mobility 46.5 cm(2) /Vs). Atomic force microscopy shows that the partial alignment is uniform over an area of 20 × 20 mm(2) and confirms that the orientation of the nanotubes is mostly along the fluid flow direction, with a narrow orientation scatter characterized by a full width at half maximum (FWHM) of <15° for all but the densest film, which is 35°. This parallel process is large-scale applicable and exploits the anisotropic properties of the SWNTs, presenting a viable path forward for industrial adoption of SWNTs in printed, flexible, and large-area electronics.