Knowledge Bank

The polarized room temperature far infrared power reflection spectra of semiconductor SnS have been analyzed by model on the factorized form of the dielectric function to yield the long wavelength phonon frequencies and lifetimes for all the principal directions. The model in inadequate for one polarization and dispersive-reflection-measurements on a small single crystal face (area $\sim 0.16cm2$) for the same orientation has allowed the experimental dielectric function to be determined for the first time. Further analysis reveals the presence of phonon self-energy and coupled phonon-plasmon effects.