Theoretically explore XRD analysis and multi-functional properties of Ruddlesden popper phase family member Sr2XO4 (X = Ce, Hf, Ti and Zr) for photovoltaic applications

Abstract

In the present study, a comprehensive theoretical investigation is carried out on the optical, mechanical, structural, thermodynamic, elastic, and electronic properties of the Ruddlesden–Popper phase Sr₂XO₄, (X = Ce, Hf, Ti, and Zr) compounds. The calculations are performed using the Generalized Gradient Approximation (GGA) in conjunction with the Perdew–Burke–Ernzerhof (PBE) functional. The computed electronic band structures reveal that these compounds exhibit either direct or indirect band gaps within the range of 1.575 to 3.083 eV, classifying them as semiconductors and indicating their strong potential for photovoltaic applications. The X-ray diffraction (XRD) analysis shows distinct diffraction peaks of varying intensities across the 2θ range of 5° to 50°, confirming the crystalline nature of the compounds. Furthermore, thermodynamic properties are analyzed using Density Functional Perturbation Theory (DFPT) and the calculated zero-point energies for the respective compounds are 0.6167 eV, 0.7310 eV, 0.7135 eV, and 0.6692 eV. The optical properties such as optical conductivity (∼5.5 fs⁻¹), dielectric constant (ranging from 5 to 7), absorption coefficient (on the order of 10⁵ cm⁻¹), and refractive index (ranging between 2 and 3) are notably high in the visible and near-ultraviolet regions, reinforcing their suitability for optoelectronic and photonic applications. Mechanical property analysis confirms their ductile nature, further validating their applicability in flexible electronic devices. Overall, this study highlights the multifunctional characteristics of Sr₂XO₄ compounds and recommends them for next-generation photovoltaic applications.