Hot Carrier Generation in Two-Dimensional Silver Nanoparticle Arrays at Different Excitation Wavelengths under On-Resonant Conditions
| Autor: | Yuki Takeuchi, Nobuyuki Takeyasu, Katsumasa Fujita, Mircea Modreanu, Tetsuya Fujita, Yasuaki Kumamoto, Takuo Tanaka, Antoine Violas |
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| Rok vydání: | 2020 |
| Předmět: |
Materials science
Silver nanoparticle 02 engineering and technology 010402 general chemistry 01 natural sciences Excitation wavelength Hot carrier Light illumination Physical and Theoretical Chemistry Surface plasmon resonance 2D Two-dimensional AgNP business.industry 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Wavelength General Energy Optoelectronics Plasmon resonance 0210 nano-technology business Excitation |
| Zdroj: | The Journal of Physical Chemistry C. 124:13936-13941 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.0c04034 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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