First-principles study on crystal structures and bulk modulus of CuInX₂ (X = S, Se, S-Se) solar cell absorber

Abstract Chalcopyrite semiconductors are widely used as absorbers in thin film solar cells, especially flexible due to their high power conversion efficiency. They also have interesting mechanical properties, making them promising materials for flexible, light, and cells. In this work, we report the first-principle calculations of lattice constant bulk modulus CuInS 2 , CuInSe CuIn(S,Se) absorber materials. All performed using plane wave implemented Quantum ESPRESSO software package framework density functional theory PBE-GGA approximations ultrasoft pseudopotentials. The calculated correlates well with available experimental study. energy-volume pressure-volume relations described third order Birch-Murnaghan’s equation state calculate material, which is associated hardness a material under particular conditions. values obtained good agreement theoretical results, except been reported first time.