Investigation of thermal dependence of phonon frequencies, sound velocity, mechanical and optical characteristics of the β-GaN semiconductor compound

In this work, the sound velocity and some of the mechanical, optical and optical phonon frequencies of the semiconductor β-GaN have been studied. The proposed temperature dependency of the pseudopotential form factors was used together with the empirical pseudopotential technique (EPM). The precise form factors for each temperature are computed using the suggested model. Calculations have been done to determine the temperature-dependent values of the energy gaps, sound velocity, refractive index, elastic constants, mechanical moduli, phonon frequencies and dielectric constants. The findings and the published and experimental data in the literature are in good agreement. These findings can be used as a guide for physical parameter values that are difficult to quantify experimentally.