Measurement of the absolute Raman scattering cross section of the 1584‐cm⁻¹ band of benzenethiol and the surface‐enhanced Raman scattering cross section enhancement factor for femtosecond laser‐nanostructured substrates

Abstract

The absolute Raman scattering cross section (σ RS ) for the 1584-cm −1 band of benzenethiol at 897 nm (1.383 eV) has been measured to be 8.9 ± 1.8 × 10 −30 cm 2 using a 785-nm pump laser. A temperature-controlled, small-cavity blackbody source was used to calibrate the signal output of the Raman spectrometer. We also measured the absolute surface-enhanced Raman scattering cross section (σ SERS ) of benzenethiol adsorbed onto a silver-coated, femtosecond laser-nanostructured substrate. Using the measured values of 8.9 ± 1.8 × 10 −30 and 6.6 ± 1.3 × 10 −24 cm 2 for σ RS and σ SERS respectively, we calculate an average cross-section enhancement factor (EF) of 0.8 ± 0.3 × 10 6 .

Metal−Molecule Schottky Junction Effects in Surface Enhanced Raman Scattering

“…Similarly, the large enhancement of 420 cm -1 peak (βCCC+ νCS), is obtained in our simulation only after taking into account of the metal molecular Schottky junction (Fig. 9), which is also consistent with the experimental observations [93,107] and theoretical prediction [44].…”

“…In fact this value is very close to the vibrational shift observed (which ranges from ~ 10-13 cm -1 ) in many SERS experiments for this particular characteristics peak [105][106][107]. In spite of not having enough statistics to prove our hypothesis, the results clearly points to a possible role of electric field of strength ~1 V/A o .…”

“…In a parallel SERS experiment reported in the paper [93,107], the SERS peak for the same mode was observed at 1573 cm -1 . Apparently the Raman peak position shifts in the SERS spectrum in comparison with the original Raman spectrum.…”

Rigorous surface enhanced Raman spectral characterization of large-area high-uniformity silver-coated tapered silica nanopillar arrays

“…Figure 1 (a) and (b) show the scanning electron microscope image of the LLNL nanopillar SERS substrate before depositing silver and after coated with 80 nm of silver respectively. After the deposition, the silver-coated LLNL substrates were then functionalized with a SAM of benzenethiol using an earlier described procedure [30]. The substrates were submerged in 4-mM solutions of benzenethiol made with ethanol for 1 h and then gently rinsed in neat ethanol for 1 min, followed by drying under a stream of nitrogen.…”

Nanopillars array for surface enhanced Raman scattering

“…2, the spatially-averaged SERS enhancement factor can be estimated using the following expression [18]:…”