TY - JOUR
T1 - Study of Chemical Enhancement Mechanism in Non-plasmonic Surface Enhanced Raman Spectroscopy (SERS)
AU - Kim, Jayeong
AU - Jang, Yujin
AU - Kim, Nam Jung
AU - Kim, Heehun
AU - Yi, Gyu Chul
AU - Shin, Yukyung
AU - Kim, Myung Hwa
AU - Yoon, Seokhyun
N1 - Funding Information:
Funding. This work was supported by Basic Science Research Program (NRF-2016R1D1A1B01009032, NRF-2016R1D1A1B03934962, NRF-2018R1A6A1A03025340) through the National Research Foundation of Korea (NRF). This work at SNU was also supported by Global Research Laboratory Program (2015K1A1A2033332), through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT.
Publisher Copyright:
© Copyright © 2019 Kim, Jang, Kim, Kim, Yi, Shin, Kim and Yoon.
PY - 2019/8/20
Y1 - 2019/8/20
N2 - 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.
AB - 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.
KW - charge transfer
KW - chemical enhancement
KW - enhancement mechanism
KW - semiconductor microstructure
KW - surface enhanced Raman scattering
UR - http://www.scopus.com/inward/record.url?scp=85072739138&partnerID=8YFLogxK
U2 - 10.3389/fchem.2019.00582
DO - 10.3389/fchem.2019.00582
M3 - Article
AN - SCOPUS:85072739138
SN - 2296-2646
VL - 7
JO - Frontiers in Chemistry
JF - Frontiers in Chemistry
M1 - 582
ER -