Understanding of Strain Condition Effects on Physical Properties of the Bi2Se3 Compound by the DFT Method

Abstract

This study investigated the structural, electronic, optical, thermodynamic, and thermoelectric properties of the Bi₂Se₃ compound when strains along distinct crystallographic directions. This compound showed a p-type semiconductor nature with a bandgap of 0.77 eV. The anisotropic behavior of the material has also been examined, providing insights into potential applications in various fields. We employed the density functional theory (DFT) under the Wien2k package. The calculations utilized the LSDA (local spin density approximation) and mBJ (modified Becke-Johnson) local density approximation functionals to handle exchange–correlation interactions. The study covered a range of characteristics, including heat capacity, Debye temperature, lattice thermal conductivity, and optical properties including the absorption coefficient, the electron energy loss, the refractive index, and the optical conductivity as well as the dielectric tensor’s real and imaginary components. The thermoelectric properties including the Seebeck coefficient, electrical conductivity, electronic contribution to thermal conductivity, and calculated power factors have been deduced and discussed.