Exploring the impact of Sr substitution on the physical characteristics of CsCdCl3 perovskite via DFT-Based analysis

The structural, electronic, optical, and thermodynamic properties of CsCdCl₃ with strontium (Sr) doping (6%, 11%, and 17%) were investigated using first-principles calculations based on the ultra-soft pseudopotential method within the Generalised Gradient Approximation (GGA). The computed structural parameters show excellent agreement with reported data. Pure CsCdCl₃ and the 6% and 11% Sr-doped systems exhibit indirect band gaps of 1.65-1.73 eV, whereas the band gap vanishes at 17% doping. Optical analyses reveal enhanced dielectric constants, strong absorption above 200,000 cm⁻¹, and improved absorption and electrical conductivity in the 20-26 eV energy range. Sr-doping also increases the refractive index and reflectivity. Thermodynamic analyses demonstrate that Sr incorporation increases heat capacity, entropy, and phonon spectrum range, suggesting improved thermal energy storage and enhanced lattice disorder. Electron Energy Loss Spectroscopy (EELS) indicates doping-induced modifications in the local electronic environments of Cs, Cd, and Cl atoms, with higher doping levels producing structural distortions and reduced electronic excitations. These findings demonstrate the potential of Sr-doped CsCdCl₃ for optoelectronic and energy-related applications, including light-emitting diodes, solar cells, radiation detectors, and energy storage devices.