Exploring the effect of hydrostatic pressure on the physical properties of non-toxic Na3OX (X = Cl, I) anti-perovskites for optoelectronic applications

Abstract

The toxicity and instability of lead compounds have made it crucial to find stable, eco-friendly substitutes for lead-based halide perovskites. In this work, we employed first-principles density functional theory (DFT) computations to examine the structural, electrical, optical, mechanical, and thermal properties of non-toxic Na₃OX (X = Cl, I) anti-perovskites under a range of hydrostatic pressures from 0 to 500 GPa. The stability of these compounds is confirmed by our structural results, which agree with earlier theoretical investigations. Both Na₃OCl and Na₃OI have relatively broad bandgaps, which are much diminished when hydrostatic pressure rises. This makes them suitable for usage in solar energy and semiconductor applications. These materials are promising candidates for optoelectronic devices such as UV detectors, waveguides, solar cell anti-reflection coatings, organic light-emitting diodes (OLEDs), and quantum dot light-emitting diodes (QLEDs) because the application of pressure results in improved optical behavior, such as increased static dielectric constants, extended absorption in the ultraviolet range, and decreased visible reflectance. Anisotropic nature, strong thermal stability, and a change from brittle to ductile behavior at high pressure are all revealed by mechanical analysis. Their suitability for use in robust device environments is further supported by the improvement in ductility and elastic characteristics under compression. All things considered, the tunability and multifunctional potential of Na₃OCl and Na₃OI anti-perovskites are demonstrated in this thorough investigation, providing important information for further study and advancement in pressure-engineered optoelectronic and energy materials.