ELECTRIC PROPERTY OF INSULATED MOLECULAR WIRE FORMED BY CONDUCTING POLYMER AND MOLECULAR NANOTUBE

最近，我们发现了一种新型的分子导线，它是由环糊精（CD）和导电聚合物聚苯胺（PANI）合成的分子纳米管形成的，并利用原子力显微镜（AFM）观察了绝缘分子导线的结构。这种包合物可以看作是绝缘的分子线，因为导电聚合物被CD分子作为绝缘体覆盖。由于用光刻技术制作间隙为100 nm的精细电极是相当困难的，我们成功地制作了SiO_2基片上的电极（电极之间的差距约为100 nm），并在此基础上制作了一种新型的分子器件。500 nm）。电极之间相互隔离，即电极之间的电阻率大于10 TΩ，这种带电极的衬底在沉积碳纳米管桥接电极之间的差距时表现出良好的性能，我们成功地沉积了绝缘分子线桥接电极之间的差距，并在国际上首次测量了单根无掺杂绝缘分子线的电导率。由于掺杂绝缘分子线具有较高的电导率，因此我们尝试对掺杂绝缘分子线进行测量。此外，我们计划测量的温度依赖性的导电性的一个单一的绝缘分子线。

We have recently found a novel kind of molecular wire formed by the molecular nanotube synthesized from cyclodextrins (CDs) and a conducting polymer, polyaniline (PANI), and observed the structure of the insulated molecular wire by atomic force microscopy (AFM). This inclusion complex can be regarded as insulated molecular wire, because a conducting polymer is covered by CD molecules as insulator. In this study, we aim to make a molecular device using a single insulated molecular wire as a material for the connection between the external electrodes.Since it is quite difficult to fabricate the fine electrodes with a gap of 100 nm scale by using photo lithography, we have successfully made SiO_2 substrates with electrodes (the gap bewtween electrodes is ca. 500 nm) by AFM lithography. Electrodes are isolated each other, that is, the resistivity between each electrodes is more than 10 TΩ, and this substrate with electrodes has shown good property when we deposited the carbon nanotube to bridge the gap between electrodes.We have successfully deposited the insulated molecular wire to bridge the gap between electrodes and measured the conductivity of a single insulated molecular wire without dope for the first time in the world. Since it is expected that the doped insulated molecular wire had high conductivity, we try to measure the doped insulated molecular wire now. Further, we plan to measure the temperature dependence of the conductivity of a single insulated molecular wire.