Raman Spectroscopy of Porous Silicon

Abstract

Raman spectroscopy is being utilized to characterize porous silicon (PS) structures, not only for optoelectronic but also for sensing applications like SERS and biomedical uses. This review focuses on the large body of work extracting nanocrystallite size distibutions from Raman signals. Raman scattering of PS can give valuable information on properties of nanosized silicon structures that strongly depend on the symmetry, structural geometry, morphology, pore diameter, skeleton size, etc. The phonon confinement model of the first order optical phonons at 521 cm À1 is often used to analyze Raman scattering band shapes of porous silicon and hence to determine the size of crystallites embedded in the porous layer. Particles of nanometric size also show low-frequency acoustic vibrational modes that can be observed by Raman spectroscopy.

Silicon Nanostructures for Molecular Sensing: A Review

“…Nanocrystalline porous silicon (pSi) is a sponge-like nanostructure, which is one of the imperative Si-compatible photonic materials widely applied in many applications such as photovoltaics, optical sensors, and biological sensors. ,− Formerly, pSi was recognized by Uhlir at Bell laboratories accidentally while performing their pioneering work on electro-polishing of Si wafer . Subsequently, Memming and Schwamdt anticipated that the observed pSi was amorphously made by electrochemical/anodic etching .…”