Probing the physical properties of LiSbX (X = Cl, F) halides perovskites for optoelectronic applications.

In this study, the structural, electronic, optical, mechanical, and phonon properties of LiSbX (X = Cl, F) halide perovskites were investigated using first-principles density functional theory (DFT) calculations. Structural stability was confirmed via the Birch-Murnaghan equation of state, revealing a cubic perovskite structure for both compounds. LiSbCl exhibited a larger lattice parameter (5.5345 Å) compared to LiSbF (4.6784 Å) due to the heavier chlorine atoms. Electronic band structure analysis confirmed their metallic nature, characterized by a continuous band of energy states. Optical analysis demonstrated strong ultraviolet absorption and reflection, with LiSbCl displaying a high dielectric constant (11.25 at 0.10 eV) and an optical conductivity peak of 4684 Ω cm at 10.54 eV, whereas LiSbF exhibited a lower dielectric constant (2.99 at 4.48 eV) and a conductivity peak of 1579 Ω cm at 13.44 eV. Mechanical stability analysis indicated that LiSbCl is ductile with a positive shear modulus (8.39 GPa), while LiSbF is mechanically unstable with a negative shear modulus (- 16.68 GPa). These findings highlight the potential of LiSbCl for energy storage, optoelectronic, and photonic applications, while further optimization is required for LiSbF to enhance its mechanical stability.