Fano Resonance in Single‐Molecule Junctions

• Published in: Angewandte Chemie International Edition Vol. 61; no. 40; pp. e202210097 - n/a
• Main Authors: Zheng, Yan, Duan, Ping, Zhou, Yu, Li, Chuan, Zhou, Dahai, Wang, Yaping, Chen, Li‐Chuan, Zhu, Zhiyu, Li, Xiaohui, Bai, Jie, Qu, Kai, Gao, Tengyang, Shi, Jia, Liu, Junyang, Zhang, Qian‐Chong, Chen, Zhong‐Ning, Hong, Wenjing
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 04.10.2022
• Edition: International ed. in English
• Subjects: Carbazole; Carbazoles; Charge Transfer; Electrical measurement; Electrochemical Gating; Electrochemistry; Electron transport; Electronic devices; Electronic equipment; Fano Resonance; Interference; Molecular orbitals; Resonance; Single-Molecule Junctions
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202210097

The Fano resonance in single‐molecule junctions could be created by interaction with discrete and continuous molecular orbitals and enables effective electron transport modulation between constructive and destructive interference within a small energy range. However, direct observation of Fano resonance remains unexplored because of the disappearance of discrete orbitals by molecule‐electrode coupling. We demonstrated the room‐temperature observation of Fano resonance from electrochemical gated single‐molecule conductance and current–voltage measurements of a para‐carbazole anion junction. Theoretical calculations reveal that the negative charge on the nitrogen atom induces a localized HOMO on the molecular center, creating Fano resonance by interfering with the delocalized LUMO on the molecular backbone. Our findings demonstrate that the Fano resonance in electron transport through single‐molecule junctions opens pathways for designs of interference‐based electronic devices. This work offers the first direct observation of the Fano resonance effect in single‐molecule junctions by the charge injection on the nitrogen atom using an EC‐STM‐BJ technique at room temperature, which provides a facile way to manipulate electron tunneling in the single‐molecule junctions and opens a new avenue toward the design of interference‐based molecular electronic devices.