Volume 135, Issue 13 e202218799
Forschungsartikel

Chemical Enhancement and Quenching in Single-Molecule Tip-Enhanced Raman Spectroscopy

Dr. Ben Yang

Dr. Ben Yang

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

These authors contributed equally to this work.

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Dr. Gong Chen

Dr. Gong Chen

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

These authors contributed equally to this work.

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Dr. Atif Ghafoor

Dr. Atif Ghafoor

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

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Yu-Fan Zhang

Yu-Fan Zhang

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

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Dr. Xian-Biao Zhang

Dr. Xian-Biao Zhang

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

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Hang Li

Hang Li

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

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Xiao-Ru Dong

Xiao-Ru Dong

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

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Rui-Pu Wang

Rui-Pu Wang

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

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Prof. Yang Zhang

Prof. Yang Zhang

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

School of Physics and Department of Chemical Physics, University of Science and Technology of China Hefei, Anhui, 230026 China

Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088 China

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Prof. Yao Zhang

Prof. Yao Zhang

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

School of Physics and Department of Chemical Physics, University of Science and Technology of China Hefei, Anhui, 230026 China

Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088 China

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Prof. Zhen-Chao Dong

Corresponding Author

Prof. Zhen-Chao Dong

Hefei National Research Center for Physical Sciences at the Microscale and CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui, 230026 China

School of Physics and Department of Chemical Physics, University of Science and Technology of China Hefei, Anhui, 230026 China

Hefei National Laboratory, University of Science and Technology of China, Hefei, 230088 China

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First published: 31 January 2023

Abstract

Despite intensive research in surface enhanced Raman spectroscopy (SERS), the influence mechanism of chemical effects on Raman signals remains elusive. Here, we investigate such chemical effects through tip-enhanced Raman spectroscopy (TERS) of a single planar ZnPc molecule with varying but controlled contact environments. TERS signals are found dramatically enhanced upon making a tip–molecule point contact. A combined physico-chemical mechanism is proposed to explain such an enhancement via the generation of a ground-state charge-transfer induced vertical Raman polarizability that is further enhanced by the strong vertical plasmonic field in the nanocavity. In contrast, TERS signals from ZnPc chemisorbed flatly on substrates are found strongly quenched, which is rationalized by the Raman polarizability screening effect induced by interfacial dynamic charge transfer. Our results provide deep insights into the understanding of the chemical effects in TERS/SERS enhancement and quenching.

Conflict of interest

The authors declare no conflict of interest.

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