Pressure-induced modifications in the structural, thermodynamic, electronic, optical and mechanical attributes of CaTiF6 perovskite halide for optoelectronic applications

Pressure-induced bandgap engineering enables researchers to design semiconducting materials according to their desired specifications. The material’s electronic band structures can be conveniently changed by applying pressure. The current work investigates the physical traits of novel halide perovskite CaTiF₆ under the response of hydrostatic pressure using the first principles analysis. The hydrostatic pressure is applied from 0 to 16 GPa, which causes an increment in the lattice constant. The exchange–correlation effects are treated with mBJ. The structural properties elaborate that the material is geometrically and thermodynamically stable. With all applied pressures, the studied material shows a declining trend in the elastic modulus values but remains ductile and anisotropic. The elastic anisotropy of CaTiF₆ is studied via the ELATE software. With the application of pressure, the bandgap is decreased from 5.67 eV to 1.87 eV, as revealed through the electronic properties. According to a thorough examination of the optical characteristics under pressure, the material’s optical traits have shifted from the UV to the visible spectrum, which elaborates that the material can absorb and emit light at longer wavelengths because of its reduced bandgap, making this material relevant for optoelectronic devices.