Electrical transport measurements for nano-junction bridged by single molecule

本工作的目的是（1）通过改进自组装分子和电子束光刻技术的组合，开发由超导体和铁磁物质组成的纳米间隙电极的制备工艺，（2）制备由包括石墨烯在内的π电子分子桥接的纳米间隙电极，并观察纳米结的载流子输运性质，（3）探索石墨烯作为沟道材料的合成。（1）采用湿法腐蚀工艺制备了Al、Nb、Ni、Co四种元素组成的纳米间隙电极。(2)研制了一种用于制作分子器件的高真空稠度系统。(3)一致性系统研究表明，电极与分子之间的锚结构是影响器件参数的重要因素之一。(4)石墨烯覆盖层的厚度控制已经通过新开发的化学气相沉积（CVD）设备实现。(5)使用生长的多层石墨烯作为沟道的场效应晶体管的电输运性质的评估已经揭示，通过CVD生长的多层石墨烯的电带与单层石墨烯的电带几乎相同。

The purpose of this work is(1) to develop the fabrication process of the nanogap electrodes composed of a superconductor and ferromagnetic substance by an improvement of a combination of self-assembled molecular and electron beam lithographic techniques,(2) to fabricate the nanogap electrodes bridged byπ-electron molecules including graphene and observe the carrier transport properties of the nano-junction, and(3) to explore the synthesis of graphene as a channel materials. The achievements are as follows(1) The fabrication process for the nanogap electrodes composed of Al, Nb, Ni and Co has been developed by applying wet etching process.(2) Consistence system under high vacuum condition for making molecular devices has been developed.(3) Consistence system has revealed that the anchor structure between the electrode and molecule is one of most important factor in the device parameters.(4) Thickness control of graphene overlayers has been achieved by a newly developed chemical vapor deposition(CVD) apparatus.(5) Evaluation of electrical transport properties of field effect transistor using grown multilayer graphene as a channel have been revealed that electrical band of multilayer graphene grown by CVD is virtually identical to that of monolayer graphene.