Investigating how the electronic and optical properties of a novel cubic inorganic halide perovskite, Sr3NI3 are affected by strain

Abstract

Background: Inorganic Perovskite materials have sparked the attention of the solar technology sector due to their remarkable structural, optical, and electrical capabilities. In the realm of efficient LEDs, inorganic perovskites have displayed considerable promise, showcasing various benefits such as exceptional color purity, the ability to adjust emission wavelengths, and cost-effective fabrication methods. Methods: The study extensively investigated the bandgap, density of states, electron charge density, structural properties, dielectric properties, loss function, and absorption coefficient of Sr3NI3 under strain using first-principles density functional theory (DFT). Results: At the Gamma (Γ) point, the unstrained flat structure of Sr3NI3 exhibits a direct band gap of 0.733 eV. Observing the spin-orbital coupling (SOC) effect reduces the bandgap to 0.711 eV in Sr3NI3 perovskite. Compressive strain minimizes the prevalence of the structure's bandgap, whereas tensile strain causes a slight elevation. The optical properties of this material, including the dielectric functions, absorption coefficient, reflectivity, and electron loss function, exhibit its excellent absorption capacity in the visible area because of its band characteristics. Conclusions: The research indicates that as the amount of compressive strain rises, the peak values of the dielectric constant of Sr3NI3 shift towards lower photon energy (redshift); meanwhile, when tensile strain is executed, it displays the behavior of altered photon energy with an increase towards higher energy levels (blueshift). Thus, the potential of utilizing Sr3NI3 perovskite in solar cells for energy production and light management is considered promising.