物理化学学报

最新录用 上一篇    下一篇

单分子器件中的新颖静电场效应

林锦亮, 张雅敏, 张浩力   

  1. 兰州大学化学化工学院, 功能有机分子化学国家重点实验室, 特殊功能材料与结构设计教育部重点实验室, 兰州 730000
  • 收稿日期:2020-05-05 修回日期:2020-06-04 录用日期:2020-06-05 发布日期:2020-06-16
  • 通讯作者: 张浩力 E-mail:Haoli.zhang@lzu.edu.cn
  • 基金资助:
    国家重点研发计划(2017YFA0204903)和国家自然科学基金(51733004, 51525303)资助项目

Novel Electrostatic Effects in Single-Molecule Devices

Jin-Liang Lin, Yamin Zhang, Hao-Li Zhang   

  1. State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Special Function Materials and Structure Design (MOE), College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China
  • Received:2020-05-05 Revised:2020-06-04 Accepted:2020-06-05 Published:2020-06-16
  • Supported by:
    The project was supported by the National Key R&D Program of China (2017YFA0204903), and the National Natural Science Foundation of China (51733004, 51525303).

摘要: 分子电子学旨在利用单个分子作为结构单元组装出功能电路以实现器件微型化。随着分子电子学的发展,各种功能器件被开发出来,很多独特的量子现象也被研究者所发现。这些突破得益于各种调控分子器件中电荷传输的刺激响应手段(例如静电场、磁场、光照、机械力和化学刺激)的运用。在众多调控方法中,利用静电场的调控方法以其独特的优势而备受关注,并且带来了许多新颖的发现。首先,和在所有电子器件中一样,静电场以非侵入的方式作用于单分子器件中。其次,不同于传统电子器件,在尺寸极小的单分子器件中施加电压可以产生极大的静电场,为调控电荷输运和催化单分子尺度化学反应等提供了必要条件。本文从常用的断裂结构筑技术展开介绍,总结静电场在调控分子-电极接触界面、分子构型和分子构象、单分子尺度化学反应、分子自旋态、分子氧化还原态、分子能级与电极能级等方面的应用。并对静电场调控在分子电子学领域内存在的一些挑战和潜在应用做了总结和展望。

关键词: 分子电子学, 单分子结, 静电场, 自旋开关, 分子晶体管, 单分子尺度化学反应

Abstract: The past decades have witnessed an increasing interest in molecular electronics aiming to assemble functional circuits using single molecules. Researchers from various disciplines have devoted considerable attention in the design and construction of single-molecule junctions and sophisticated functional devices, accompanied by the discovery and utilization of numerous novel quantum phenomena. Many new breakthroughs benefit from the utilization of various stimulus response methods to tune the charge transport in molecular devices, such as light, temperature, magnetic field, pH, and mechanical force. Electrostatic field has superb but distinct abilities to modulate the charge transport in molecular devices. First, like in other electronic devices, electrostatic fields act on single-molecule devices as a noninvasive means. However, unlike in these traditional electronic devices, the voltage applied in the extremely tiny single-molecule devices would generate a large electrostatic field, which could provide the necessary conditions for regulating charge transport and catalyzing single-molecule-scale chemical reactions. This review focuses on the recent advances made in tuning charge transport by electrostatic field in the single-molecule devices. In the second section, we introduce and compare two break junction techniques commonly used to construct molecular junctions: the scanning tunneling microscopy break junction (STMBJ) technique and the mechanically controllable break junction (MCBJ) technique; furthermore, the three-electrode systems based on these two break junction techniques are also introduced. These techniques laid the foundation for various new techniques in tuning charge transport in molecular junctions based on electrostatic field. In the third section, the applications of electrostatic field are introduced, including controlling the molecular-electrode interfaces, varying molecule configurations and conformations, catalyzing single-molecule-scale chemical reactions, switching molecule spin states, changing molecule redox states and shifting the energy levels of the electrodes and molecules. Finally, we discussed the shortcomings of the applications electrostatic field in single-molecule devices. Including the low stability of single-molecule devices under strong electrostatic field, and the introduction of electrostatic field will increase the difficulty of understanding the charge transport mechanism in single-molecule devices. In addition, we point out that electrostatic field modulation of single-molecule charge transport is expected to be further developed in the following aspects: Firstly, multi-stimulus response molecule devices could be built by combining electrostatic field with other stimulus. Secondly, electrostatic field could be used to catalyze more types of chemical reactions, even control the configurations and conformations of products. Thirdly, electrostatic field can be used to design fullerene-based switching molecular diodes that proper for application in random-access memories and memristors.

Key words: Molecule electronics, Single-molecule junction, Electrostatic field, Spin switch, Molecular transistor, Single-molecule-scale chemical reaction

MSC2000: 

  • O641