Lattice dynamics behavior in GaN doped with Mg, As, Si, and C

We present a lattice dynamics study based on Buckingham potential for wurtzite GaN doped with donor and acceptor impurities: Mg, As, Si and C. We have evaluated the formation energies of the defect levels for all impurities. Local vibrational modes in the region of the acoustical and optical phonons are also presented. For Mg and As impurities, we confirm the origin of vibrational modes observed previously. Besides, possible frequencies for the local vibrational mode in GaN doped with Si and C are presented.