DFT-Based Study of Structural, Electronic, Optical and Elastic Properties of CdGeAs₂ and CdSnAs₂ Chalcopyrires

This study reports a comprehensive first-principles investigation of the chalcopyrite semiconductors CdGeAs2 and CdSnAs2, with particular emphasis on their structural, electronic, optical, and elastic properties. The calculations were carried out within the density functional theory (DFT) framework using the full-potential linearized augmented plane wave (FP-LAPW) method. The optimized equilibrium structural parameters, including lattice constants a and c as well as the internal coordinate u, show very good consistency with available experimental measurements and earlier theoretical predictions. Band structure calculations confirm that both compounds exhibit direct band gaps, which makes them attractive candidates for photovoltaic and optoelectronic devices. Additionally, the optical response exhibits strong absorption within the visible region, while the calculated elastic constants confirm the mechanical stability of these materials.