COMPUTATIONAL EXPLORATION OF THE DIVERSE FUNCTIONAL PROPERTIES OF DOUBLE ANTIPEROVSKITE MATERIALS Na 6 AgBiX 2 (X = Cl, Br, I)

Abstract

The ongoing study investigates optoelectronic as well as photovoltaic characteristics of double antiperovskite (DAP) compounds Na6AgBiX2 (X = Cl, Br, I) using Density Functional Theory (DFT) with semi-classical Boltzmann Transport theory calculations, aiming at potential applications renewable energy technologies. Optimization of DAP Na6AgBiX2 (X = Cl, Br, I) show lattice constants (a) of ∼ 11 Å, which are increased from its counter double perovskite. For the stability of these compounds were tested by Formation enrgy (E f ), binding energy (E b ), Goldschmidt tolerance factor τG, elastically and thermodynamics. Electronic calculations reveal Na6AgBiCl2 and Na6AgBiBr2 possess direct bandgaps with energies 1.27 eV and 1.22 eV, respectively, whereas Na6AgBiI2 displays an indirect band gap of 1.15 eV. The electron charge density reflects the balance ionic and covalent interactions in these compounds. According to optical characteristics All substances exhibit considerable absorbing power in the visible area. Photocatalytic studies indicated that Na6AgBiX2 (X = Cl, Br, I) show good response for oxidation. The greatest value of ZT of 0.79 at 300 K among compounds indicates that N a6AgBiBr2 may be a promising candidate for TE application, according to TE characteristics. The solar cell efficiency predited by SLME, N a6AgBiBr2 have high efficiency of 8.46% than N a6AgBiCl2 (@8.06%) and N a6AgBiI2 (@8.12%) at for 0.5 µm thick layer. Which is further increase to over 30% with increase in thickness. All these findings underscore the potential of Na6AgBiCl2 for advanced renewable energy applications (such as optoelectronics, water splitting, Thermoelectric and photovoltaics).