Raman Spectra of Confined LO Phonons in Single Heterostructure

抄録

We present a theoretical description of the Raman spectra from longitudinal optical (LO) phonon modes confined in a heterostructure consisting of a thin surface layer on a semi-infinite substrate. The scattering cross section is derived by a dispersive continuum model for ionic displacement on the basis of classical response function theory. The spectra calculated for GaAs/AlGaAs reveal that phonon confinement in GaAs layer leads to asymmetric feature in line shape as well as peak shifts of the GaAs-type modes. The observability of the confined LO modes via Raman studies is discussed.