Tip-enhanced resonance Raman spectroscopy and imaging of a single molecule

Authors

  • Rafael B. Jaculbia Surface and Interface Science Laboratory, RIKEN, Wako

Abstract

In optical spectroscopy experiments, the diffraction limit restricts the spatial resolution of measurements to half the wavelength of light used, making optical based techniques particularly challenging for nanoscale materials. For Raman spectroscopy in particular, an additional challenge is the inherently low conversion efficiency of the Raman scattering effect. Tip-enhanced Raman spectroscopy (TERS) is one of the techniques that can break both the diffraction limit and the low signal intensity in Raman spectroscopy. In TERS, the tip of a scanning probe microscope such as a scanning tunnelling microscope (STM) is brought close to the target sample. The tip boosts both the incident and Raman scattered radiation leading to several orders of magnitude increase in the signal allowing the spatial resolution to be well below the diffraction limit. In previous works, STM-TERS was shown to have both vibrational mode selectivity and less than 1 nm spatial resolution. This achievement however, was obtained by severely perturbing the molecule’s electronic structure. In this talk, I will present our recent works on tip-enhanced Raman spectroscopy in ultrahigh vacuum and low temperature environments. We have achieved single molecule Resonance spectroscopy by utilizing an ultrathin sodium chloride film. The sodium chloride film allows us to perform TERS while keeping the original electronic structure of the molecule. The Raman maps show sensitivity to vibrational mode symmetry with 1 nm spatial resolution. Such a technique can be useful in the discovery of new materials and new material functions.

About the Speaker

Rafael B. Jaculbia, Surface and Interface Science Laboratory, RIKEN, Wako

Rafael Jaculbia is a special postdoctoral researcher in The Institute of Physical and Chemical Research (RIKEN), Japan. He is a member of the Surface and Interface Science Laboratory in the Cluster for Pioneering Research in RIKEN under Dr. Yousoo Kim. His current work is on nearfield optics, in particular tip-enhanced Raman spectroscopy of single molecules and he is also developing a nearfield scattering type terahertz microscope. He obtained his B.S., M.S., and PhD in Physics from the University of the Philippines Diliman in 2009, 2011, and 2016, respectively. In 2016, he received the Edgardo Gomez Award for outstanding research from the College of Science in University of the Philippines Diliman.

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Published

2020-10-19

How to Cite

[1]
RB Jaculbia, Tip-enhanced resonance Raman spectroscopy and imaging of a single molecule, Proceedings of the Samahang Pisika ng Pilipinas 38, SPP-2020-INV-4F-03 (2020). URL: https://proceedings.spp-online.org/article/view/SPP-2020-INV-4F-03.