Study of Chemical Enhancement Mechanism in Non-plasmonic Surface Enhanced Raman Spectroscopy (SERS)

Jayeong Kim, Yujin Jang, Nam Jung Kim, Heehun Kim, Gyu Chul Yi, Yukyung Shin, Myung Hwa Kim, Seokhyun Yoon

Research output: Contribution to journalArticlepeer-review

45 Scopus citations

Abstract

Surface enhanced Raman spectroscopy (SERS) has been intensively investigated during the past decades for its enormous electromagnetic field enhancement near the nanoscale metallic surfaces. Chemical enhancement of SERS, however, remains rather elusive despite intensive research efforts, mainly due to the relatively complex enhancing factors and inconsistent experimental results. To study details of chemical enhancement mechanism, we prepared various low dimensional semiconductor substrates such as ZnO and GaN that were fabricated via metal organic chemical vapor deposition process. We used three kinds of molecules (4-MPY, 4-MBA, 4-ATP) as analytes to measure SERS spectra under non-plasmonic conditions to understand charge transfer mechanisms between a substrate and analyte molecules leading to chemical enhancement. We observed that there is a preferential route for charge transfer responsible for chemical enhancement, that is, there exists a dominant enhancement process in non-plasmonic SERS. To further confirm our idea of charge transfer mechanism, we used a combination of 2-dimensional transition metal dichalcogenide substrates and analyte molecules. We also observed significant enhancement of Raman signal from molecules adsorbed on 2-dimensional transition metal dichalcogenide surface that is completely consistent with our previous results. We also discuss crucial factors for increasing enhancement factors for chemical enhancement without involving plasmonic resonance.

Original languageEnglish
Article number582
JournalFrontiers in Chemistry
Volume7
DOIs
StatePublished - 20 Aug 2019

Keywords

  • charge transfer
  • chemical enhancement
  • enhancement mechanism
  • semiconductor microstructure
  • surface enhanced Raman scattering

Fingerprint

Dive into the research topics of 'Study of Chemical Enhancement Mechanism in Non-plasmonic Surface Enhanced Raman Spectroscopy (SERS)'. Together they form a unique fingerprint.

Cite this