Polarized Raman Spectra and N-Related Local Vibrational Mode in GaNAs and GaInNAs Epitaxial Layers Grown on GaAs

摘要

Raman studies were performed on GaN_(0.025)As_(0.975) and Ga_(0.94)In_(0.06)N_(0.025)As_(0.975) epilayers grown on (100) GaAs. N alloying enhanced the forbidden TO phonon, while In alloying had a negligible effect on it. The forbidden TO phonon had an A_1 symmetry, in contrast to that of Ga_(0.969)In_(0.031) As having a T_2 symmetry. In GaInNAs, thermal annealing led to the splitting of a N-related local vibrational mode (LVM) into a doublet (472 and 490 cm~(-1)), while no change was observed in GaNAs. LVM is discussed in terms of In-N bond formation.