Conductance of a Single Conjugated Polymer as a Continuous Function of Its Length
Conductance of a Single Conjugated Polymer as a Continuous Function of Its Length
复制标题
DOI：
10.1126/science.1168255
复制
发表时间：
2009-02-27
期刊：
影响因子：
56.9
通讯作者：
Grill, Leonhard
中科院分区：
文献类型：
--
作者：
Lafferentz, Leif;Ample, Francisco;Grill, Leonhard
单分子尺度电子器件的开发需要详细了解通过单个分子线的电荷传输。为了表征电导率，有必要以受控方式改变与两个电极接触的单分子线的长度。此类研究通常确定具有特定长度的某种分子种类的电导率。我们通过用扫描隧道显微镜的尖端将单根聚芴线从 Au(111) 表面拉起，从而连续改变其长度直至超过 20 纳米，从而测量单根聚芴线的电导和机械特性。电导曲线不仅显示出指数衰减，而且还显示出在拉伸过程中一个又一个分子单元从表面分离时的特征振荡。
The development of electronic devices at the single-molecule scale requires detailed understanding of charge transport through individual molecular wires. To characterize the electrical conductance, it is necessary to vary the length of a single molecular wire, contacted to two electrodes, in a controlled way. Such studies usually determine the conductance of a certain molecular species with one specific length. We measure the conductance and mechanical characteristics of a single polyfluorene wire by pulling it up from a Au(111) surface with the tip of a scanning tunneling microscope, thus continuously changing its length up to more than 20 nanometers. The conductance curves show not only an exponential decay but also characteristic oscillations as one molecular unit after another is detached from the surface during stretching.