First-principles investigation of lead-free halide perovskites RbBCl 3 (B = Fe, Co) for magneto-optoelectronic and thermoelectric devices

In this study, a comprehensive density functional theory (DFT) investigation was carried out to examine the structural, electronic, magnetic, optical, and thermoelectric properties of the lead-free halide perovskites RbBCl 3 (B= Fe, Co). The calculations were performed using the GGA+U and TB-mBJ+U approaches within the full-potential linearized augmented plane-wave (FP-LAPW) framework. The optimized structures confirm a stable cubic perovskite phase with space group Pm-3 m, supported by favorable tolerance factors and negative formation energies. The mechanical stability was verified through the Born–Huang criteria, indicating ductile behavior for RbFeCl 3 and higher rigidity for RbCoCl 3 . The spin-polarized…