DFT simulation to study the physical properties of ternary intermetallic materials ACuSb (A=Ca, Sr, Ba) for solar cell and TBC materials

Abstract

This study carried out the configurational, bulk, electronic, optical as well as thermodynamic features of ternary materials ACuSb (A = Ca,Sr, Ba) using first-principles DFT-based calculations. The explored lattice constants as well as unit cell volume are very close to hypothetical results which make sure the correctness of the present study. According to the investigated elastic stiffness constants, the studied compounds are mechanically stable as they hold the Born's stability criteria. Utilizing the calculated values of elastic constants the several polycrystalline parameters such as elastic moduli (B, Y, E), machinability index (μm), hardness (HV), Poisson's ratio, Pugh's and isotropic/anisotropic factor of ACuSb (A = Ca,Sr, Ba) have been calculated and discussed in details. Very high machinability indices of these phases ensure their industrial applications. Since the values of Poisson's and Pugh's are ν < 0.26 and B/G < 0.75, therefore the phases ACuSb (A = Ca,Sr, Ba) show brittle manner. The direction-dependent features of these materials are confirmed from the Universal anisotropy factor analysis. Band structure analysis reveals that every compounds exhibit metallic character. Bond population analysis revealed the different covalent and ionic bonding tendencies in these compounds, with apparent differences in the nature of Cu–Sb bonds. Furthermore, the absorption coefficients of BaCuSb ensures its excellent suitability for solar cell applications, as it demonstrated remarkable UV-range absorption capabilities, distinguishing it from the other compounds in this regard. The thermal analysis demonstrated that these compounds exhibit remarkably low thermal conductivity, indicating their appropriate applications in thermal barrier coating (TBC) materials.