Effects of structural distortion on electronic and optical properties of defect CdGa₂X₄ (X = S, Se, Te) Chalcopyrite Semiconductor

We observe significant effects of structural distortion on electronic and optical properties of CdGa_2X_4 (X = S, Se, Te) defect chalcopyrite. The calculation is carried out within Density functional theory based tight binding linear muffin tin orbital (TB-LMTO) method. Structural parameters and band gap of CdGa_2X_4 agree well with the available experimental values within LDA limit. Change in band gap due to structural distortion is 3.63%, 4.0%, and 8.8% respectively. We observe significant change in optical properties also due to this effect. Effects on optical properties come mainly from optical matrix elements. Our results of these response functions agree well with the available experimental values.