A split in the frequencies between the longitudinal-optic (LO) phonon modes in the dipole-allowed and dipole-forbidden geometries is observed in ion-etched InP by Raman scattering. Dipole-forbidden LO-phonon scattering has been reported in pure as well as mixed crystals; however, a frequency split has been observed only in AlxGa1-xAs crystals. The observation of this split in InP is attributed to a relaxation of the selection rules due to the structural disorder induced by ion etching.
ASJC Scopus subject areas
- Condensed Matter Physics