Essay On Raman Spectroscopy

Raman spectroscopy is capable of depth profile, in-situ kinetic measurement and temperature calculation. Combining with SERS sensor, the weak Raman scattering could be dramatically enhanced, which is usually called Surface-enhance Raman spectroscopy (SERS). It will provide a powerful technique to observe very subtle bond variation information in ultra-thin film samples and interphases.

This study attempts to understand the in-situ kinetic surface nano-structure, reaction and interfacial analysis by using Raman spectroscopy. The main techniques are SERS with several types of SERS sensor, temperature calculation from anti-Stokes Raman scattering, depth profile with a step of 1 angstrom. The analysis was completed with atomistic resolution, high quality, kinetically and in situ. In following sections, all the techniques employed in this study for analyzing interfacial reaction, will be introduced one by one.

1.1.1 Raman spectroscopy

Raman spectroscopy is a vibrational spectroscopy technique used to collect a unique chemical fingerprint of molecules, based on the Raman scattering (Figure 1.1) found by Indian scientist C.V. Raman. The process of Raman spectroscopy work involves the inelastic scattering of a beam of monochromatic light by a sample material. Usually, a laser is irradiated on a sample for

In the 1970s, scientists discovered the SERS phenomenon, in which pyridine molecules were absorbed onto a roughened silver surface, resulting in a significant enhancement of the Raman signals [2]. It was found that SERS can enhance the scattering effect markedly, even up to 1014 times the common Raman signal [3], which overcame the low sensitivity of the common Raman technique. The enhancement is mainly owing to the amplification of the light resulting from the excitation of localized surface plasmon resonances