Thomas James O, Sowa Jakub K, Limburg Bart, Bian Xinya, Evangeli Charalambos, Swett Jacob L, Tewari Sumit, Baugh Jonathan, Schatz George C, Briggs G Andrew D, Anderson Harry L, Mol Jan A
Department of Materials, University of Oxford Parks Road Oxford OX1 3PH UK
Department of Chemistry, University of Oxford, Chemistry Research Laboratory Oxford OX1 3TA UK.
Chem Sci. 2021 Jul 26;12(33):11121-11129. doi: 10.1039/d1sc03050g. eCollection 2021 Aug 25.
Electron-electron interactions are at the heart of chemistry and understanding how to control them is crucial for the development of molecular-scale electronic devices. Here, we investigate single-electron tunneling through a redox-active edge-fused porphyrin trimer and demonstrate that its transport behavior is well described by the Hubbard dimer model, providing insights into the role of electron-electron interactions in charge transport. In particular, we empirically determine the molecule's on-site and inter-site electron-electron repulsion energies, which are in good agreement with density functional calculations, and establish the molecular electronic structure within various oxidation states. The gate-dependent rectification behavior confirms the selection rules and state degeneracies deduced from the Hubbard model. We demonstrate that current flow through the molecule is governed by a non-trivial set of vibrationally coupled electronic transitions between various many-body ground and excited states, and experimentally confirm the importance of electron-electron interactions in single-molecule devices.
电子-电子相互作用是化学的核心，理解如何控制它们对于分子尺度电子器件的发展至关重要。在此，我们研究了通过一个氧化还原活性边缘融合卟啉三聚体的单电子隧穿，并证明其输运行为可用哈伯德二聚体模型很好地描述，这为电子-电子相互作用在电荷输运中的作用提供了见解。特别是，我们通过实验确定了分子的在位和位间电子-电子排斥能，其与密度泛函计算结果高度吻合，并建立了各种氧化态下的分子电子结构。栅极依赖的整流行为证实了从哈伯德模型推导的选择规则和态简并性。我们证明，通过分子的电流由各种多体基态和激发态之间一组非平凡的振动耦合电子跃迁所支配，并通过实验证实了电子-电子相互作用在单分子器件中的重要性。
