Probe enhanced, nano-Raman spectroscopy (PERS); A sensitive technique for vibrational surface spectroscopy

Vibrational spectroscopy, which is considered one of the most definitive means of obtaining chemical bonding information, often has a low measurement sensitivity preventing its application to the study of interfaces and monolayers. Surface plasmons induced on metal nano-particles by electromagnetic radiation (e.g. light) can be used to enhance the sensitivity and spatial resolution (below the optical diffraction limit) of spectroscopic techniques like Raman scattering. Significant enhancements to the scattering cross-section, sometimes by as much as 10, make possible the detection of even single molecules. This work reports on the development of probe enhanced Raman spectroscopy (PERS) which uses near field, metallic nano-probes to study technologically significant silicon interfaces with high sensitivity.