Ab initio investigation of the pressure dependences of phonon and dielectric properties for III-V semiconductors

Theoretical results of a first-principles plane-wave pseudopotential study on the phonon and dielectric properties for the nitrides, phosphides, and arsenides of Al, Ga, and In under hydrostatic pressure are presented. The pressure dependences of the dielectric constant, phonon frequencies at the Γ point, polarity, and localized and non-localized effective charges are calculated. We found that the dielectric constant, dynamic effective charge, and polarity decrease, while the localized effective charge and optical phonon frequencies increase with pressure for all these III-V phases. The distinctive behaviours as regards lattice dynamics of these compounds are explained on the basis of the non-localized to localized charge transference inside the crystal under pressure