Effect of structural phase transformations under pressure on electronic and optical properties of CuInS2

First-principle calculations based on the density functional theory were carried out to study the phase transitions of chalcopyrite CuInS2 (CIS) under pressure. We confirmed that CIS transforms from the tetragonal I4¯2d structure into the cubic Fm3¯m phase at 7.9 GPa. As the pressure increases, a new possible phase transition for CIS from the cubic Fm3¯m structure to the orthorhombic Cmcm structure under higher pressure was predicted occurring at 49.6 GPa. The semiconductor material CIS changes into a metallic material when the pressure is above 7.9 GPa. Our study will spark continued interest in the field of pressure-induced structural phase transition for CIS.241