Characterization of Coulomb Interactions in Electron Transport through a Single Hetero-Helicene Molecular Junction Using Scanning Tunneling Microscopy

Fuente: arXiv
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Main Authors: Shi, Yueqing, Bi, Liya, Wang, Zihao, Liang, Kangkai, Li, Ji-Kun, Wang, Xiao-Ye, Li, Wan-Lu, Li, Shaowei
Format: Preprint
Published: 2024
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author Shi, Yueqing
Bi, Liya
Wang, Zihao
Liang, Kangkai
Li, Ji-Kun
Wang, Xiao-Ye
Li, Wan-Lu
Li, Shaowei
author_facet Shi, Yueqing
Bi, Liya
Wang, Zihao
Liang, Kangkai
Li, Ji-Kun
Wang, Xiao-Ye
Li, Wan-Lu
Li, Shaowei
contents Characterization of the structural and electron transport properties of single chiral molecules provides critical insights into the interplay between their electronic structure and electrochemical environments, providing broader implications given the significance of molecular chirality in chiroptical applications and pharmaceutical sciences. Here, we examined the topographic and electronic features of a recently developed chiral molecule, B,N-embedded double hetero[7]helicene, at the edge of Cu(100) supported NaCl thin film with scanning tunneling microscopy and spectroscopy. An electron transport energy gap of 3.2 eV is measured, which is significantly larger than the energy difference between the highest occupied and the lowest unoccupied molecular orbitals given by theoretical calculations or optical measurements. Through first principles calculations, we demonstrated that this energy discrepancy results from the Coulomb interaction between the tunneling electron and the molecule's electrons. This occurs in electron transport processes when the molecule is well decoupled from the electrodes by the insulating decoupling layers, leading to a temporary ionization of the molecule during electron tunneling. Beyond revealing properties concerning a specific molecule, our findings underscore the key role of Coulomb interactions in modulating electron transport in molecular junctions, providing insights into the interpretation of scanning tunneling spectroscopy features of molecules decoupled by insulating layers.
format Preprint
id arxiv_https___arxiv_org_abs_2409_16485
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Characterization of Coulomb Interactions in Electron Transport through a Single Hetero-Helicene Molecular Junction Using Scanning Tunneling Microscopy
Shi, Yueqing
Bi, Liya
Wang, Zihao
Liang, Kangkai
Li, Ji-Kun
Wang, Xiao-Ye
Li, Wan-Lu
Li, Shaowei
Chemical Physics
Characterization of the structural and electron transport properties of single chiral molecules provides critical insights into the interplay between their electronic structure and electrochemical environments, providing broader implications given the significance of molecular chirality in chiroptical applications and pharmaceutical sciences. Here, we examined the topographic and electronic features of a recently developed chiral molecule, B,N-embedded double hetero[7]helicene, at the edge of Cu(100) supported NaCl thin film with scanning tunneling microscopy and spectroscopy. An electron transport energy gap of 3.2 eV is measured, which is significantly larger than the energy difference between the highest occupied and the lowest unoccupied molecular orbitals given by theoretical calculations or optical measurements. Through first principles calculations, we demonstrated that this energy discrepancy results from the Coulomb interaction between the tunneling electron and the molecule's electrons. This occurs in electron transport processes when the molecule is well decoupled from the electrodes by the insulating decoupling layers, leading to a temporary ionization of the molecule during electron tunneling. Beyond revealing properties concerning a specific molecule, our findings underscore the key role of Coulomb interactions in modulating electron transport in molecular junctions, providing insights into the interpretation of scanning tunneling spectroscopy features of molecules decoupled by insulating layers.
title Characterization of Coulomb Interactions in Electron Transport through a Single Hetero-Helicene Molecular Junction Using Scanning Tunneling Microscopy
topic Chemical Physics
url https://arxiv.org/abs/2409.16485