We adopted the time-dependent density functional theory (TDDFT) within the linear augmented Slater-type orbitals (LASTO) basis and the cluster averaging method to compute the { \color{ red}excitation} spectra of III-V ternary alloys with arbitrary concentration $x$. The TDDFT was carried out with the use of adiabatic meta-generalized gradient approximation (mGGA), which contains the $1/q^2$ singularity in the dynamical exchange-correlation kernel ($f_{ XC,00}(\mathbf{ q})$) as $q\rightarrow 0$. We found that by using wave functions obtained in local density approximation (LDA) while using mGGA to compute self-energy correction to the band structures, we can get { \color{ red} good overall} agreement between theoretical results and experimental data for the excitation spectra. Thus, our studies provide some insight into the theoretical calculation of optical spectra of semiconductor alloys.
Categories: physics.comp-ph cond-mat.mtrl-sci
