2018年2月
Fluctuation in Interface and Electronic Structure of Single-Molecule Junctions Investigated by Current versus Bias Voltage Characteristics
Journal of the American Chemical Society
- ,
- ,
- ,
- 巻
- 140
- 号
- 10
- 開始ページ
- 3760
- 終了ページ
- 3767
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/jacs.7b13694
- 出版者・発行元
- American Chemical Society ({ACS})
Structural and electronic detail at the metal-molecule interface has a significant impact on the charge transport across the molecular junctions, but its precise understanding and control still remain elusive. On the single-molecule scale, the metal-molecule interface structures and relevant charge transport properties are subject to fluctuation, which contain the fundamental science of single-molecule transport and implication for manipulability of the transport properties in electronic devices. Here, we present a comprehensive approach to investigate the fluctuation in the metal-molecule interface in single-molecule junctions, based on current-voltage (I-V) measurements in combination with first-principles simulation. Contrary to conventional molecular conductance studies, this I-V approach provides a correlated statistical description of both the degree of electronic coupling across the metal-molecule interface and the molecular orbital energy level. This statistical approach was employed to study fluctuation in single-molecule junctions of 1,4-butanediamine (DAB), pyrazine (PY), 4,4′-bipyridine (BPY), and fullerene (C60). We demonstrate that molecular-dependent fluctuation of σ-, π-, and π-plane-type interfaces can be captured by analyzing the molecular orbital (MO) energy level under mechanical perturbation. While the MO level of DAB with the σ-type interface shows weak distance dependence and fluctuation, the MO level of PY, BPY, and C60 features unique distance dependence and molecular-dependent fluctuation against the mechanical perturbation. The MO level of PY and BPY with the σ+π-type interface increases with the increase in the stretch distance. In contrast, the MO level of C60 with the π-plane-type interface decreases with the increase in the stretching perturbation. This study provides an approach to resolve the structural and electronic fluctuation in the single-molecule junctions and insight into the molecular-dependent fluctuation in the junctions.
- リンク情報
- ID情報
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- DOI : 10.1021/jacs.7b13694
- ISSN : 0002-7863
- eISSN : 1520-5126
- ORCIDのPut Code : 87579936
- PubMed ID : 29470910
- SCOPUS ID : 85043773831