VIBRATIONAL MODES OF OXYGEN IN GALLIUM PHOSPHIDE.

Abstract

The authors present a theoretical description of the vibrational modes of oxygen in GaP. With a single free parameter, the overall force constant between oxygen and the lattice, chosen to match experiment, good agreement is found between experiment and theory for most of the observed phonon modes of the positive and neutral charge states of the defect. The results indicate that all of the phonon-related features observed in optical spectra of the defect can be understood within the 'classical' description of Dean and co-workers. The authors, predict the existence of low energy localized modes, originating from transverse-acoustic bulk phonons, which should be observed for most defect pairs and other complexes.