The significant disparity between the size and electronegativity of N and group-V (P, As, Sb) atoms in dilute III–V-Ns remains a cornerstone for developing the next-generation electronics. Variations in the structural, optical, and phonon properties of the quaternary GaAs1−x−ySbyNx alloys are being used for improving the high-performance photovoltaic energy and optoelectronic technologies. Bandgap Eg tunability has assisted efficient light emission/detection to cover the crucial optical fiber wavelengths for the low-cost integrated chips in data communications and sensing devices. The lattice dynamical properties of these materials are critical for assessing the reliability to evaluate the performance of long-wavelength lasers, photodetectors, and multi-junction solar cells. Our systematic Raman measurements on high-quality MBE grown GaAs0.946Sb0.032N0.022/GaAs samples have detected ωTO(Γ)GaAs and ωTO(Γ)GaAs phonons along with a high frequency NAs local mode near ~476 cm−1. Weak phonon structures on both sides of the broad 476 cm−1 band are interpreted forming a complex NAs–Ga–SbAs defect center. Using a realistic rigid-ion model in the Green’s function framework, the simulations of impurity modes for isolated and complex defects have provided corroboration to the experimental data.
Talwar et al. (Sat,) studied this question.