Reduction-Controlled Viologen in Bisolvent as an Environmentally Stable n-Type Dopant for Carbon Nanotubes
Reduction-Controlled Viologen in Bisolvent as an Environmentally Stable n-Type Dopant for Carbon Nanotubes
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DOI：
10.1021/ja807480g
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发表时间：
2009-01-14
影响因子：
15
通讯作者：
Lee, Young Hee
中科院分区：
文献类型：
--
作者：
Kim, Soo Min;Jang, Jin Ho;Lee, Young Hee
通过直接氧化还原反应，各种暴力剂被用于控制单壁碳纳米管（SWCNTs）的掺杂。介绍了一种用甲苯和紫素溶解水双相萃取中性紫素（V-0）的新方法。硼氢化钠还原剂将带正电的紫素（V2+）转移到V-0中，还原后的V-0分离为甲苯，分离率高。将分离后的VI溶液滴在碳纳米管晶体管上，研究碳纳米管的掺杂效果。当紫外光浓度为3 mM时，所有的p型碳纳米管都转化为n型晶体管，并提高了开关比。这是通过从中性V-0自发地向碳纳米管提供电子来实现的，从而在纳米管表面再次留下能量稳定的V2+。由于在最外层的碳纳米管晶体管中存在疏水性V-0，掺杂的碳纳米管在水中是稳定的，这可以作为保护层来防止水的进一步氧化。
Various viologens have been used to control the doping of single-walled carbon nanotubes (SWCNTs) via direct redox reactions. A new method of extracting neutral viologen (V-0) was introduced using a biphase of toluene and viologen-dissolved water. A reductant of sodium borohydride transferred positively charged viologen (V2+) into V-0, where the reduced V-0 was separated into toluene with high separation yield. This separated VI solution was dropped on carbon nanotube transistors to investigate the doping effect of CNTs. With a viologen concentration of 3 mM, all the p-type CNT transistors were converted to n-type with improved on/off ratios. This was achieved by donating electrons spontaneously to CNTs from neutral V-0, leaving energetically stable V2+ on the nanotube surface again. The doped CNTs were stable in water due to the presence of hydrophobic V-0 at the outermost CNT transistors, which may act as a protecting layer to prevent further oxidation from water.