基于异形SAM的金属-分子-金属连接处的接触电阻:表面链接器和金属加工功能的影响
Jeremy M Beebe1, Vincent B Engelkes, Larry L Miller
1Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Journal of the American Chemical Society
|September 19, 2002
概括
分子道结点是使用各种金属接触和自组装单层来创建的. 接触电阻取决于金属加工功能和链接器类型,表明费米水平接近HOMO.
科学领域:
- 材料科学 材料科学 材料科学
- 表面化学 表面化学
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 分子电子学旨在使用单个分子作为电子元件.
- 了解通过分子层的电荷传输对于设备开发至关重要.
- 金属有机接口显著影响分子连接的电子特性.
研究的目的:
- 为了研究分子道连接处的接触电阻.
- 为了确定金属加工功能与接口电阻之间的关系.
- 探索不同分子连接剂 (醇与异二烯) 对接触电阻的影响.
主要方法:
- 使用基乙醇和基异二烯自组装单层形成分子道连接.
- 使用导探探头原子力显微镜 (CP-AFM) 进行连接制造.
- 测量低偏差的连接阻力作为链长度的函数.
主要成果:
- 接触电阻 (R0) 通过推断到零链长度来确定.
- R0对金属接触类型 (Ag,Au,Pd,Pt) 有很强的依赖.
- 随着金属加工功能的增加,R0降低了 (R0,Ag > R0,Au > R0,Pd > R0,Pt).
- 与醇链接剂相比,异乙烯链接剂的金结R0降低了约10%,而醇链接剂则降低了约10%.
结论:
- 分子连接的费米级别位于接近最高占用分子轨道 (HOMO) 的位置,而不是最低不占用分子轨道 (LUMO).
- 金属加工功能是确定分子连接处接触电阻的关键因素.
- 可优化分子链接器的选择,以调整连接属性.
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