Investigating the effects of hydrostatic pressure on the physical properties of cubic SrBCl (B = As, Sb) for improved optoelectronic applications: A DFT study.

This article explores changes in the structural, electronic, elastic, and optical properties of the novel cubic SrBCl (B = As, Sb) with increasing pressure. This research aims to decrease the electronic band gap of SrBCl (B = As, Sb) by applying pressure, with the objective of enhancing the optical properties and evaluating the potential of these compounds for use in optoelectronic applications. It has been revealed that both the lattice parameter and cell volume exhibit a declining pattern as pressure increases. At ambient pressure, analysis of the band structure revealed that both SrAsCl and SrSbCl are direct band gap semiconductors. With increasing pressure up to 25 GPa the electronic band gap of SrAsCl (SrSbCl) reduces from 1.70 (1.72) eV to 0.35 (0.10) eV. However, applying hydrostatic pressure enables the attainment of optimal bandgaps for SrAsCl and SrSbCl, offering theoretical backing for the adjustment of SrBCl (B = As, Sb) perovskite's bandgaps. The electron and hole effective masses in this perovskite exhibit a gradual decrease as pressure rises from 0 to 25 GPa, promoting the conductivity of both electrons and holes. The elastic properties are calculated using the Thermo-PW tool, revealing that they are anisotropic, ductile, mechanically stable, and resistant to plastic deformation. Importantly, these mechanical properties of both compounds are significantly enhanced under pressure. Optical properties, including the absorption and extinction coefficients, dielectric function, refractive index, reflectivity, and loss function, were calculated within the 0-20 eV range under different pressure conditions. The calculated optical properties highlight the versatility and suitability of SrAsCl and SrSbCl perovskites for pressure-tunable optoelectronic devices.