Department of Chemical Engineering, Stanford University, Stauffer III, Stanford, CA 94305-5025, USA.
ACS Nano. 2009 Dec 22;3(12):4089-97. doi: 10.1021/nn900827v.
Ultrathin, transparent electronic materials consisting of solution-assembled nanomaterials that are directly integrated as thin-film transistors or conductive sheets may enable many new device structures. Applications ranging from disposable autonomous sensors to flexible, large-area displays and solar cells can dramatically expand the electronics market. With a practical, reliable method for controlling their electronic properties through solution assembly, submonolayer films of aligned single-walled carbon nanotubes (SWNTs) may provide a promising alternative for large-area, flexible electronics. Here, we report SWNT network TFTs (SWNTntTFTs) deposited from solution with controllable topology, on/off ratios averaging greater than 10(5), and an apparent mobility averaging 2 cm(2)/V.s, without any pre- or postprocessing steps. We employ a spin-assembly technique that results in chirality enrichment along with tunable alignment and density of the SWNTs by balancing the hydrodynamic force (spin rate) with the surface interaction force controlled by a chemically functionalized interface. This directed nanoscale assembly results in enriched semiconducting nanotubes yielding excellent TFT characteristics, which is corroborated with mu-Raman spectroscopy. Importantly, insight into the electronic properties of these SWNT networks as a function of topology is obtained.
由溶液组装纳米材料直接集成的超薄透明电子材料，可用作薄膜晶体管或导电片，这可能会催生许多新的器件结构。从一次性自供电传感器到柔性大面积显示器和太阳能电池等各种应用，可能会极大地拓展电子产品市场。通过溶液组装来控制其电子性能的实用、可靠方法，如果使用的是经定向排列的单壁碳纳米管（SWNTs）亚单层薄膜，那么对于大面积柔性电子器件来说，它可能是一种很有前途的替代品。在此，我们报告了通过溶液沉积具有可控拓扑结构的 SWNT 网络 TFT（SWNTntTFT），其开关比平均值大于 10(5)，迁移率平均值为 2 cm(2)/V.s，且没有任何预处理或后处理步骤。我们采用了一种自旋组装技术，通过平衡由化学官能化界面控制的表面相互作用力与流体动力（旋转速度），实现了手性富集以及 SWNTs 的可调取向和密度。这种定向纳米级组装产生了丰富的半导体纳米管，从而获得了优异的 TFT 特性，这一点得到了微拉曼光谱的证实。重要的是，我们获得了有关这些 SWNT 网络拓扑结构的电子特性的深入了解。
