Jin Yongdong, Friedman Noga, Sheves Mordechai, Cahen David
Department of Organic Chemistry, Weizman Institute of Science, Rehovot 76100, Israel.
Langmuir. 2008 May 20;24(10):5622-6. doi: 10.1021/la703859a. Epub 2008 Apr 10.
Molecular electronics is very much about contacts, and thus understanding of any generic contact effect is essential to its advance. For example, it is still not obvious in how far variations in electrode roughness of macroscopic contacts can lead to rectification. Here we report an investigation of this contact effect on electronic transport properties using metal-insulator-metal planar junctions with a 5 nm thick bacteriorhodopsin-based insulator as model system. We demonstrate that the experimentally observed rectifying behavior is not an intrinsic property of the molecules used, but rather of the local contact quality. Even a slight increase in surface roughness of the bottom electrode gives rise to distinct rectifying behavior in these and, by extrapolation, possibly other molecular junctions.
分子电子学很大程度上与接触有关，因此理解任何一般的接触效应对于其发展至关重要。例如，宏观接触的电极粗糙度变化在多大程度上会导致整流现象仍不明确。在此，我们报告了一项利用以5纳米厚的基于细菌视紫红质的绝缘体作为模型系统的金属 - 绝缘体 - 金属平面结来研究这种接触效应及其对电子输运性质影响的实验。我们证明，实验观察到的整流行为并非所用分子的固有特性，而是局部接触质量的特性。底部电极表面粗糙度的轻微增加就会在这些结中产生明显的整流行为，并且由此推断，可能在其他分子结中也会如此。
