TY - JOUR
T1 - Hot Carrier Generation in Two-Dimensional Silver Nanoparticle Arrays at Different Excitation Wavelengths under On-Resonant Conditions
AU - Takeuchi, Yuki
AU - Violas, Antoine
AU - Fujita, Tetsuya
AU - Kumamoto, Yasuaki
AU - Modreanu, Mircea
AU - Tanaka, Takuo
AU - Fujita, Katsumasa
AU - Takeyasu, Nobuyuki
N1 - Funding Information:
N.T. thanks the ASCENT program (no. 55) in European Nanoelectronics for financial support to visit Tyndall National Institute. N.T. also thanks Okayama University for the financial support to organize a symposium for plasmonics/SERS. M.M. acknowledges the support from European Union H2020 Grant 899598 and Renishaw UK for access to the InVia Qontor Raman facility.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/6/25
Y1 - 2020/6/25
N2 - We evaluated the hot carrier generation in two-dimensional (2D) silver nanoparticle (AgNP) arrays under light illumination at different wavelengths, 458, 532, 671, and 785 nm. The 2D AgNP arrays were tailored to match the plasmon resonance to each excitation wavelength in order to fulfill the on-resonant condition. We selected para-aminothiophenol (p-ATP) as a probe molecule, which is chemically transformed into 4,4′-dimercaptoazobenzene (DMAB) upon light illumination. The reaction is driven by hot carriers emitted from a plasmonic surface. For evaluation of hot carrier generation, we monitored the chemical transformation from p-ATP into DMAB with surface-enhanced Raman scattering. The normalized Raman intensity of DMAB was plotted against the total exposure, where the peak intensity increased as the total exposure increased because of the increase of the number of DMAB molecules. The saturation of the peak growth was observed, indicating that the chemical transformation was completed, at different exposures for each wavelength. The total exposure required for completing the chemical transformation was smaller at 458 nm by at least ∼105 times than that at 785 nm, although the difference of the photon energy was only 1.7 times. The growth of the Raman peak was related to the laser intensity as well, where the higher laser intensity showed a more rapid growth. These results indicated that more hot carriers with sufficient energy for the chemical transformation were generated at shorter excitation wavelengths as well as at higher laser intensities.
AB - We evaluated the hot carrier generation in two-dimensional (2D) silver nanoparticle (AgNP) arrays under light illumination at different wavelengths, 458, 532, 671, and 785 nm. The 2D AgNP arrays were tailored to match the plasmon resonance to each excitation wavelength in order to fulfill the on-resonant condition. We selected para-aminothiophenol (p-ATP) as a probe molecule, which is chemically transformed into 4,4′-dimercaptoazobenzene (DMAB) upon light illumination. The reaction is driven by hot carriers emitted from a plasmonic surface. For evaluation of hot carrier generation, we monitored the chemical transformation from p-ATP into DMAB with surface-enhanced Raman scattering. The normalized Raman intensity of DMAB was plotted against the total exposure, where the peak intensity increased as the total exposure increased because of the increase of the number of DMAB molecules. The saturation of the peak growth was observed, indicating that the chemical transformation was completed, at different exposures for each wavelength. The total exposure required for completing the chemical transformation was smaller at 458 nm by at least ∼105 times than that at 785 nm, although the difference of the photon energy was only 1.7 times. The growth of the Raman peak was related to the laser intensity as well, where the higher laser intensity showed a more rapid growth. These results indicated that more hot carriers with sufficient energy for the chemical transformation were generated at shorter excitation wavelengths as well as at higher laser intensities.
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U2 - 10.1021/acs.jpcc.0c04034
DO - 10.1021/acs.jpcc.0c04034
M3 - Article
AN - SCOPUS:85087925363
VL - 124
SP - 13936
EP - 13941
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 25
ER -