Computational insights into the multifunctional properties of Li2AgBiX6 (X=Cl, Br, I) double perovskite materials

We investigate the potential of Li2AgBiX6 2 AgBiX 6 (X = Cl, Br, I) double perovskites for optoelectronic and transport applications using density functional theory. Structural stability is confirmed through lattice constant, tolerance factor, and formation enthalpy calculations. Using the HSE-06 functional, we determine indirect bandgaps of 1.78, 1.76, and 0.92 eV for Cl, Br, and I compositions, respectively. Maximum optical absorption occurs in the visible region, supporting their potential in optoelectronic devices. Spectroscopic limited maximum efficiency calculations reveal Li2AgBiI6 2 AgBiI 6 as the most efficient (29.3 %) due to higher absorbance. We evaluate thermoelectric properties using the Boltzmann semi-classical approach and assess mechanical stability through elastic constants. Thermodynamic properties, including Debye temperature and melting point, are calculated. Magnetic property calculations indicate zero magnetic moment. The comprehensive analysis of structural, electronic, optical, transport, elastic, thermodynamic, and magnetic properties provide valuable insights into these promising double perovskite materials for various applications.