The 149th AMCP Open Seminar

Thursday, October 31, 2019, 15:00-16:00

National Institute for Materials Science (NIMS)
Sengen Main Bldg. 8F Middle Seminar Room

Pre-registration is not required.
For inquiries, please contact the Administrative Office.
This lecture is open to the public. Your participation is strongly encouraged.

Prof. Zhenchao Dong
Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China

STM-based single-molecule optical spectroscopy

The nanocavity defined by the coinage-metal tip and substrate in a scanning tunneling microscope (STM) can provide highly localized and dramatically enhanced electromagnetic fields upon proper plasmonic resonant tuning, which can modify the excitation and emission of a single molecule inside the nanocavity and produce intriguing new optoelectronic phenomena. In this talk, I shall demonstrate two STM-based phenomena related to single-molecule optical spectroscopy. The first is single-molecule Raman scattering [1]. The spatial resolution of tip enhanced Raman spectromicroscopy has been further driven down to a single chemical-bond scale. Such simultaneous energetically and spatially resolved capability for vibrational-mode mapping opens up a new possibility to determine molecular chemical structure by optical imaging at only a single molecule. The second phenomenon is single-molecule electroluminescence [2]. Our recent research on its excitation mechanism and single-photon emission behavior will be briefly presented. I shall also demonstrate how sub-nanometer resolved electroluminescence imaging can be used to gain insights into the intramolecular vibronic coupling and intermolecular dipole-dipole coupling in real space.

References:
1. R. Zhang, Y. Zhang, Z. C. Dong*, S. Jiang, C. Zhang, L. G. Chen, L. Zhang, Y. Liao, J. Aizpurua, Y. Luo, J. L. Yang, and J. G. Hou*, Nature 498, 82-85 (2013).
2. Y. Zhang, Y. Luo, Y. Zhang, Y. J. Yu, Y. M. Kuang, L. Zhang, Q. S. Meng, Y. Luo, J. L. Yang, Z. C. Dong*, and J. G. Hou*, Nature 531, 623-627 (2016).