Molecular Rectifiers on Silicon: High Performance by Enhancing Top-Electrode/Molecule Coupling
Molecular Rectifiers on Silicon: High Performance by Enhancing Top-Electrode/Molecule Coupling
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DOI：
10.1021/acsami.9b02315
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发表时间：
2019-05-22
影响因子：
9.5
通讯作者：
Jurchescu, Oana D.
中科院分区：
文献类型：
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作者：
Lamport, Zachary A.;Broadnax, Angela D.;Jurchescu, Oana D.
分子整流器是最简单的分子级电子器件之一。尽管在理解这些系统的结构性质关系方面做出了相当大的努力，但具有可预测和稳定电子性质的器件尚未开发。在这里，我们展示了在硅上形成自组装单层的新型化合物中的高效电流整流。我们通过利用分子与顶部电极的耦合来实现这一点，这反过来又控制了相关分子轨道的位置。该分子由一个硅烷锚定基团和一个氮取代苯环组成，由丙基和亚胺连接分开，是一个简单、稳定、高产的合成过程。我们发现，当这些化合物加入到分子二极管中时，根据其结构的不同，它们可以整流电流高达3个数量级，在(E)-1-（4-氰苯）- n -（3-（三乙氧基硅基）丙基）甲亚胺中获得的最大整流比为2635（平均R-avg = 1683 +/- 458，施加电压为2 V）。这种性能与金属电极上获得的最佳分子整流器相当，但它具有成本更低和与当前硅技术更有效集成的优势。硅上分子整流器的发展可能会产生杂交系统，这种系统可以将硅的用途扩展到由接枝到其表面的分子物种控制的新功能。
One of the simplest molecular-scale electronic devices is the molecular rectifier. In spite of considerable efforts aimed at understanding structure property relationships in these systems, devices with predictable and stable electronic properties are yet to be developed. Here, we demonstrate highly efficient current rectification in a new class of compounds that form self-assembled monolayers on silicon. We achieve this by exploiting the coupling of the molecules with the top electrode which, in turn, controls the position of the relevant molecular orbitals. The molecules consist of a silane anchoring group and a nitrogen-substituted benzene ring, separated by a propyl group and imine linkage, and result from a simple, robust, and high-yield synthetic procedure. We find that when incorporated in molecular diodes, these compounds can rectify current by as much as 3 orders of magnitude, depending on their structure, with a maximum rectification ratio of 2635 being obtained in (E)-1-(4-cyanophenyl)-N-(3-(triethoxysilyl) propyl)methanimine (average R-avg = 1683 +/- 458, at an applied voltage of 2 V). This performance is on par with that of the best molecular rectifiers obtained on metallic electrodes, but it has the advantage of lower cost and more efficient integration with current silicon technologies. The development of molecular rectifiers on silicon may yield hybrid systems that can expand the use of silicon toward novel functionalities governed by the molecular species grafted onto its surface.