Optical Characterizations and Electronic Devices of Nearly Pure (10,5) Single-Walled Carbon Nanotubes

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• 作者：Li Zhang^† ; ; Xiaomin Tu^‡ ; ; Kevin Welsher^† ; ; Xinran Wang^† ; ; Ming Zheng^‡ ; ; Hongjie Dai^† ;
• 刊名：Journal of the American Chemical Society
• 出版年：2009
• 出版时间：February 25, 2009
• 年：2009
• 卷：131
• 期：7
• 页码：2454-2455
• 全文大小：177K
• 年卷期：v.131,no.7(February 25, 2009)
• ISSN：1520-5126

文摘

It remains an elusive goal to achieve high-performance single-walled carbon nanotube (SWNT) field-effect transistors (FETs) composed of only single-chirality SWNTs. Many separation mechanisms have been devised and various degrees of separation demonstrated, yet it is still difficult to reach the goal of total fractionation of a given nanotube mixture into its single-chirality components. Chromatography has been reported to separate small SWNTs (diameter ≤0.9 nm) according to their diameter, chirality, and length. The separation efficiency decreased with increasing tube diameter when the ssDNA sequence d(GT)_n (n = 10−45) was used. Here we report our results on the separation of single-chirality (10,5) SWNTs (diameter = 1.03 nm) from HiPco tubes using ion-exchange chromatography. The separation efficiency was improved by using the new DNA sequence (TTTA)₃T, which can recognize SWNTs with the specific chirality (10,5). The chirality of the separated tubes was examined by optical absorption, Raman, photoluminescence excitation/emission, and electrical transport measurements. All of the spectroscopic methods gave a single peak of (10,5) tubes. The purity was 99% according to the electrical measurement. The FETs composed of separated SWNTs in parallel gave an I_on/I_off ratio up to 10⁶ due to the single-chirality-enriched (10,5) tubes. This is the first time that SWNT FETs with single-chirality SWNTs have been achieved. The chromatography method has the potential to separate even larger diameter semiconducting SWNTs from other starting materials to further improve the performance of the SWNT FETs.