  A comparison of experimentally observed Raman scattering data with Raman
line-shapes, generated theoretically using phonon confinement model, has been
carried out to understand the sensitivity of different Raman spectral
parameters on quantum confinement effect. Size dependent variations of full
width at half maximum (FWHM), Raman peak position and asymmetry ratio have been
analyzed to establish the sensitivity of their corresponding physical
counterparts (phonon life time and dispersion) in confined systems. The
comparison has been done in three different confinement regimes namely, weakly,
moderately and strongly. Proper reasoning has been assigned for such a
variation after validation of the theoretical analysis with the experimental
observations. A moderately confined system was created by preparing 6 nm sized
Si NSs using metal induced etching. An asymmetrically broadened and red-shifted
Raman line-shape was observed which established that all the parameters get
affected in moderately confined system. Sensitivity of a given Raman spectral
parameters has been shown to be used as a tool to understand the role of
external perturbations in a material.
