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通过M-m-M结的电子传输:扫描不同的CP-AFM研究

Electron Transport Through M-m-M Junctions: A Scanning Differential CP-AFM Investigation
课程网址: http://videolectures.net/slonano07_scaini_ett/  
主讲教师: Denis Scaini
开课单位: 同步加速器的里雅斯特
开课时间: 2008-02-12
课程语种: 英语
中文简介:
导电尖端AFM(CT AFM)通常用于有机和无机分子表面系统的电学表征。了解分子水平的电荷传输对于开发具有不寻常特性的分子组件对于新型应用(例如分子电子器件和传感器)至关重要。通过分子和通过分子测量电荷传输将提供对分子内和分子之间以及界面处的电子耦合的重要见解。从更一般的观点来看,这些研究旨在扩展我们对电子传输过程的基本理解,这是生物物理学和化学的核心问题。在这项工作中,我们遵循金属分子金属表面连接的研究方法,该方法使用不同基于AFM的技术的组合。我们首先使用Nanografting将感兴趣分子的纳米片构建到通常由烷硫醇制成的宿主参考自组装单层(SAM)中。在将尖端改变为导电尖端之后,CT AFM用于在整个系统记录的同时表征系统地形。这种方法的一些优点是可以以相对的方式并排构建和研究各种不同的单层膜,克服绝对测量的所有问题,并且对宿主单层的质量进行原位控制。以及嫁接补丁的那些。初步结果证明该技术的可靠性将在烷(金)(111)表面上自发组装和纳米接枝的烷硫醇。此外,我们将证明,对于一个特定长度的烷硫醇分子,即C10,纳米移植到相同分子的SAM地毯中,当前图像中出现对比,这可能与内部分子堆积的更高质量相关纳米片相对于周围的SAM。
课程简介: Conductive Tip AFM (CT-AFM) is commonly used for electrical characterization of organic and inorganic molecular surface systems. Understanding charge transport at the molecular level is of crucial importance for developing molecular assemblies with uncommon properties for novel applications, such as molecular electronic devices and sensors. Measurements of the charge transport at the contacts and through molecules will provide crucial insight into the electronic coupling within and between molecules and at the interface. From a more general point of view such studies aim at expanding our fundamental understanding of electron-transport processes, that is a central issue of biophysics and chemistry. In this work we follow an approach to the study of Metal-molecule-Metal surface junctions that uses a combination of different AFM-based techniques. We first use Nanografting to build nanopatches of the molecules of interest into a hosting reference self assembled monolayer (SAM) typically made of alkanethiols. After the tip is changed to a conductive one, CT-AFM is used to characterize electrically the whole system recording, at the same time, the system topography. Some of the advantages of this approach are the possibility to build and study a wide range of different monolayers side-by-side in a relative way, overcoming all the problems of an absolute measure, and the in-situ control of the quality both of the hosting monolayer and that of the grafted patches. Preliminary results demonstrating the reliability of the technique will be presented for alkanethiols spontaneously self-assembled and nanografted on Au(111) surfaces. Moreover, we will show that in the case of alkanethiol molecules of one specific length, i.e. C10, nanografted into a SAM carpet of the same molecules, a contrast in current images appears, that can be correlated to the higher quality of the molecular packing inside the nanopatches with respect to the surrounding SAM.
关 键 词: 导电尖端; 电子传输; 纳米移植
课程来源: 视频讲座网
最后编审: 2021-05-14:yumf
阅读次数: 66