Probing the physical properties of LiSbX3 (X = Cl, F) halides perovskites for optoelectronic applications.

In this study, the structural, electronic, optical, mechanical, and phonon properties of LiSbX₃ (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. LiSbCl₃ exhibited a larger lattice parameter (5.5345 Å) compared to LiSbF₃ (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 LiSbCl₃ displaying a high dielectric constant (11.25 at 0.10 eV) and an optical conductivity peak of 4684 Ω^-1 cm^-1 at 10.54 eV, whereas LiSbF₃ exhibited a lower dielectric constant (2.99 at 4.48 eV) and a conductivity peak of 1579 Ω^-1 cm^-1 at 13.44 eV. Mechanical stability analysis indicated that LiSbCl₃ is ductile with a positive shear modulus (8.39 GPa), while LiSbF₃ is mechanically unstable with a negative shear modulus (- 16.68 GPa). These findings highlight the potential of LiSbCl₃ for energy storage, optoelectronic, and photonic applications, while further optimization is required for LiSbF₃ to enhance its mechanical stability.