First Principles Study Of Cdsias2 Semiconductor Compound: Bulk, (100) And (001) Surfaces

For acquiring a reasonable description of the structural, electronic, optical of CdSiAs2 pnictide semiconductor and its surface structure in (100) and (001) growth direction, first principle calculations have been computed by DFT implemented in WIEN2k. PBE- sol exchange correlation functions along with a more advanced technique namely, modified Becke Johnson exchange potential (mBJ-GGA) have been used for the calculations since mBJ gives results closer to the experimental value of band gap. Lattice constant, band gap and density of states (DOS) have been calculated. Bulk CdSiAs2 exhibits a direct band gap of 1.46 eV and major contribution to the density of states is from the Cd-d states while the surface structures of CdSiAs2 with 10 A thickness evidence metallic nature. While the reflectivities of both surfaces and bulk are optimal from UV to IR range, optical properties of bulk chalcopyrite CdSiAs2, computed in terms of dielectric constant, absorption coefficient, reflectivity and refractive index, show that absorption is high in ultraviolet and visible regions of energy spectrum thereby making it suitable for photonic and optical applications.