Effect of Low to High Pressure on the Structural, Mechanical, Electrical, and Optical Properties of Inorganic Material CaAsBr: An Ab Initio Investigation.

Inorganic metal halide solar cells made from perovskite stand out for having outstanding efficiency, cheap cost, and simple production processes and recently have generated attention as a potential rival in photovoltaic technology. Particularly, lead-free CaAsBr inorganic materials have a lot of potential in the renewable industry due to their excellent qualities, including thermal, electric, optoelectronic, and elastic features. In this work, we thoroughly analyzed the stress-driven structural, mechanical, electrical, and optical properties of CaAsBr utilizing first-principles theory. The unstressed planar CaAsBr compound's bandgap results in 1.63 eV, confirming a direct bandgap. The bandgap within this compound could have changed by applying hydrostatic stress; consequently, a semiconductor-to-metallic transition transpired at 50 GPa. Simulated X-ray diffraction further demonstrated that it maintained its initial cubic form, even after external disruption. Additionally, it has been shown that an increase in compressive stress causes a change of the absorption spectra and the dielectric function with a red shift of photon energy at the lower energy region. Because of the material's mechanical durability and increased degree of ductility, demonstrated by its stress-triggered mechanical characteristics, the CaAsBr material may be suitable for solar energy applications. The mechanical and optoelectronic properties of CaAsBr, which are pressure sensitive, could potentially be advantageous for future applications in optical devices and photovoltaic cell architecture.