Unraveling lead-free Fr-based perovskites FrQCl3 (Q = Ca, Sr) and their pressure induced physical properties: DFT analysis for advancing optoelectronic performance
Asif Hosen, Md. Adil Hossain, Mohammed S. Abu-Jafar, Redi Kristian Pingak, Ahmad A. Mousa
Abstract
A comprehensive study of structural, electronic, elastic, and optical properties of the cubic FrQCl 3 (Q = Ca, Sr) perovskite under pressure 0 − 105 GPa has been considered. Interestingly, FrCaCl 3 experiences a shift from an indirect to a direct bandgap material at 12 GPa, while FrSrCl 3 undergoes the same shift at 10 GPa, rendering these materials more advantageous for application in optoelectronic devices . As pressure rises, the electronic density of states increases near the Fermi level by shifting valence band electrons upward. This leads to a reduction in the bandgap and a shift of the bandgap from the ultraviolet to the visible region. The examination of mechanical properties indicates that FrQCl 3 (Q = Ca, Sr) perovskite exhibits significant potential for uses requiring a combination of anisotropic , and ductile behavior. Optical property analysis reveals that with an increase in hydrostatic pressure , dielectric constant's peak of both material shift towards lower photon energy area.