Abstract
It is shown that dispersions of E1 (LO) and A1 (LO) modes of InN can be restored in a wide interval of wave vectors by studying impurity-induced first-order Raman scattering as a function of exciting light energy. It is also shown that due to the resonance character of scattering the observed phonon energies correspond to the wave vectors strictly defined by exciting photon energies. The frequencies of E1 (LO) and A1 (LO) phonons at the Γ point obtained by extrapolation to zero wave vectors were found to be 604 and 592 cm-1, respectively. © 2009 The American Physical Society.