在Si(100) 上堆叠pi的乙分子线的导电路
Manuel Smeu1, Robert A Wolkow, Hong Guo
1Center for the Physics of Materials and Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8. smeum@physics.mcgill.ca
Journal of the American Chemical Society
|July 17, 2009
概括
制造分子电子元件是一项挑战. 这项研究表明,基板可以提供意想不到的导电路径,影响分子线性能,并要求在理论分析中考虑基板效应.
科学领域:
- 分子电子学分子电子学
- 材料科学是一种材料科学.
- 凝聚物质物理学 凝聚物质物理学
背景情况:
- 在固态基板上对分子功能组件的系统制造仍然是分子电子学的关键挑战.
- 最近的进展使得乙基分子线在H端的Si100) 表面上能够自组装.
研究的目的:
- 从理论上分析基板上pi堆叠的乙分子线的电荷传输特性.
- 为了研究基板对传导通路和电阻缩放的影响.
主要方法:
- 利用了第一原理密度函数理论 (DFT) 与非平衡格林函数 (NEGF) 形式主义相结合.
- 开发了一种设备模型,该模型是以乙堆叠在H端的Si(100) 表面桥梁金属导线上.
- 计算了电子传输光谱,散射状态和分子电线电阻.
主要成果:
- 传输光谱显示在HOMO-LUMO附近的共振,但Si基板在费米水平附近提供了显著的导电路.
- 在费米水平附近的主导导通路被发现是通过Si基板,而不是分子线.
- 分子线的电阻在两个方案中随着长度 (R ~ e^(beta*n)) 呈指数增长:分子堆 (高β) 和基板 (低β).
结论:
- 通过半导体基板进行导电可以是分子电子设备的重要因素.
- 对半导体基板上的分子线的理论分析必须考虑基板介导导路径.
- 了解这些双导电模式对于设计和优化分子电子元件至关重要.
更多相关视频
相关概念视频
01:24π Molecular Orbitals of 1,3-Butadiene
Conjugated dienes have lower heats of hydrogenation than cumulated and isolated dienes, making them more stable. The enhanced stabilization of conjugated systems can be understood from their π molecular orbitals.
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...
01:22Semiconductors
There is variation in the electrical conductivity of materials - metals, semiconductors, and insulators that are showcased with the help of the energy band diagrams.
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...
Metals such as copper (Cu), zinc (Zn), or lead (Pb) have low resistivity and feature conduction bands that are either not fully occupied or overlap with the valence band, making a bandgap non-existent. This allows electrons in the highest energy levels of the valence band to easily transition to the conduction band upon gaining...