Present study addresses critical knowledge gaps by systematically studying the ground state structural, electronic, photocatalytic, mechanical and optical, characteristics of RbCdX 3 (X = F, Cl, Br) halide perovskites via first-principles calculations. The ground state formation energy and elastic tensor analysis establish that the compounds are mechanically and energetically stable. The calculated band structure reveals that all the structures exhibit indirect bandgap characteristics and values of 5.53, 3.87, and 2.77 eV for the RbCdF 3 , RbCdCl 3 and RbCdBr 3 structures, respectively. The bonding character of different interatomic bonds is explained by Mulliken and −pCOHP analysis. The calculated redox potentials indicate that RbCdCl 3 and RbCdBr 3 structures are suitable as photocatalysts for water separation and the degradation of environmental contaminants. The estimated various elastic parameters indicate that all the materials are elastically ductile, soft, and anisotropic, with high machinability, highlighting their mechanical robustness for practical applications. Phonon dispersion analysis indicates that RbCdF 3 and RbCdBr 3 exhibit dynamical stability, whereas RbCdCl 3 is dynamically unstable. The overlap between the acoustic and low-frequency optical phonon modes in the RbCdF 3 and RbCdBr 3 compounds is linked to reduced thermal conductivity and enhanced transport properties. Optical properties with strong absorption in the UV region and high transparency in the visible region, indicate potential for optical applications such as window materials and UV absorbers. This detailed investigation highlights the opportunities of RbCdX 3 (X = F, Cl, Br) perovskites in optoelectronic and photocatalytic devices, providing the groundwork for future experimental and theoretical studies.
Jannat et al. (Mon,) studied this question.