Raman phonon modes of zinc blende InxGa1−xN alloy epitaxial layers

Transverse-optical (TO) and longitudinal-optical (LO) phonons of zinc blende InxGa1−xN (0⩽x⩽0.31) layers are observed through first-order micro-Raman scattering experiments. The samples are grown by molecular-beam epitaxy on GaAs (001) substrates, and x-ray diffraction measurements are performed to determine the epilayer alloy composition. Both the TO and LO phonons exhibit a one-mode-type behavior, and their frequencies display a linear dependence on the composition. The Raman data reported here are used to predict the A1 (TO) and E1 (TO) phonon frequencies of the hexagonal InxGa1−xN alloy.