Strain effect on the physical properties of novel Mg3NI3 perovskite material: First principle DFT analysis

Abstract

Inorganic perovskite-based substances have become a major attraction to solar technology. Inorganic cubic ${\text{Mg}}_{3}N{I}_3$ perovskites have generated a heap of fascination owing to their distinctive optical, electrical, and structural features. The photovoltaic and optoelectronic industries prioritize lead-free, atomically tailored metal halide perovskites due to the need to address lead (Pb) toxicity and instability. This study assessed the optical, structural, and electrical parameters of Pb-free inorganic halide perovskites ${\text{Mg}}_{3}N{I}_3$ as a function of biaxial compressive and tensile strain, leveraging first-principles density-functional theory (FP-DFT). Refractive index, absorption coefficient, reflectivity, dielectric function, and tolerance factor are a few additional optical parameters that are computed and processed. The bandgap of the planar ${\text{Mg}}_{3}N{I}_3$ molecule is 0.412 eV (PBE) when SOC is not applied. The bandgap reduces to 0.363 eV (PBE) at its Γ(gamma) and R-point when the subjective SOC effect is taken into consideration. This compound's bandgap will narrow under tensile strain and expand under compressive strain, depending on whether the SOC effect is applied or not. Several elastic factors are anticipated, including the bulk modulus, Pugh's ratio, elastic constants, anisotropic factors, and Poisson's ratio. Electronic property calculations using band mechanism and density of states (DOS) suggest that ${\text{Mg}}_{3}N{I}_3$ have a bandgap that is indirect and semiconductive. The elastic properties of this material were found to be mechanically stable, anisotropic, and ductile. In the photon energy range suitable for solar cells, the spikes in the dielectric constant of ${\text{Mg}}_{3}N{I}_3$ are seen. Our findings point to the prospect of ${\text{Mg}}_{3}N{I}_3$ as a non-toxic, high-performance, low-cost material for implementation in solar cells and different semiconductor devices.