Reversible Temperature Dependence in Surface-Enhanced Raman Scattering of 1-Propanethiol Adsorbed on a Silver Island Film

Abstract

Intensity of the surface-enhanced Raman scattering (SERS) of 1-propanethiol adsorbed on a silver film prepared chemically has been measured over the 15-300 K surface temperature range. A reversible change in the SERS intensity with the temperature has been observed, with the intensity at 15 K being larger than that at 300 K by a factor of ∼3. Various factors that can affect the SERS intensity such as the laser-induced change in surface morphology, adsorption and desorption, and destruction of adatoms could be eliminated as a possible cause for the observed temperature dependence. Enhancement of the Raman intensity has been calculated over the experimental temperature range based on the electromagnetic (EM) model for SERS proposed by Gersten and Nitzan. It has been found that the observed temperature dependence can be explained qualitatively with the EM model calculation.

Inherent Complexities of Trace Detection by Surface‐Enhanced Raman Scattering

“…[105][106][107] One method for reducing laser-induced molecular degradation is to lower the sample temperature. For example, by conducting SERS experiments at 40 K, Pang et al [108] have shown that the negative effects of laser exposure can be greatly reduced. In general, lowering the sample temperature has several desirable effects, such as: less sample degradation due to laser damage, better analyte adsorption, and a suppression of analyte diffusion, which, in the sm-SERS regime, results in fewer spectral fluctuations.…”

Interesting substrate-temperature dependence on surface-enhanced Raman scattering

“…As we know, SERS technologies are generally applied to two systems of adsorbates [9] and deposited species [10]. On the other hand, as shown in the literature, substrate-temperature dependences of SERS below and above room temperature were widely investigated through theoretical and experimental studies [11][12][13][14]. All of these studies indicate that the SERS enhancement in general decreases as substrate-temperature decreases.…”

Effects of substrate temperatures on improved surface-enhanced Raman scattering

“…In SERS studies, two different analysis systems of adsorbates [20] and deposited species [21] are generally employed. On the other hand, as shown in the literature, substrate-temperature dependences of SERS below and above room temperature were widely investigated through theoretical and experimental studies [22][23][24][25]. All of these studies indicate that the SERS enhancement in general decreases as substrate temperature decreases.…”