Electronic and Optical Tuning in CsXF 3 (X = Sn, Ge, Zn, Sr) Cubic Fluoride Perovskites: A DFT Approach
Year: 2026
Type: article
Abstract: Lead‐free cubic CsXF 3 (X = Sn, Ge, Zn, Sr) fluoride perovskites are promising, environmentally friendly candidates for sustainable optoelectronic technologies. In this work, their structural, energetic, lattice dynamical, and broadband optical properties are systematically investigated using density functional theory (DFT). Comparative functional assessments demonstrate that the generalized gradient approximation of Perdew–Burke–Ernzerhof (GGA‐PBE) method provides superior structural accuracy over PBE revised for solids (PBEsol) and successfully curbs the artificial atomic over‐binding inherent to local density approximation (LDA). Total energy and Goldschmidt tolerance factor analyses confirm robust thermodynamic stability against decomposition. However, harmonic phonon dispersion calculations reveal critical dynamical instabilities within the ideal cubic lattice at 0 K for CsSnF 3 , CsGeF 3 , and CsSrF 3 due to pronounced imaginary modes, whereas CsZnF 3 exhibits near‐complete dynamic stability. Beyond structural profiles, this research emphasizes how diverse electronic configurations customize each compound for targeted device architectures. Specifically, the direct bandgaps of CsSnF 3 (1.74 eV) and CsGeF 3 (2.04 eV), combined with high optical conductivity, position them as exceptional visible‐light harvesting photovoltaic absorbers. Conversely, the wide transparency windows and localized wide‐bandgap profiles of CsZnF 3 (3.64 eV) and CsSrF 3 (6.29 eV) optimize them for solar‐blind photodetectors and deep‐ultraviolet (UV) optical windows, respectively. Crucially, planar average charge density and electrostatic potential analyses reveal that lone‐pair‐driven strong internal electric fields tailor CsSnF 3 and CsGeF 3 for active ferroelectric applications, whereas the uniform ionic charge distribution of CsZnF 3 and CsSrF 3 favors their utilization as reliable gate insulators and energy storage capacitors. Finally, spin–orbit coupling (SOC) assessments confirm that relativistic effects are negligible. Ultimately, these theoretical insights establish critical microscopic design guidelines for fluoroperovskite‐based energy technologies.
DOI: 10.1155/acmp/9157716
Author: Taha Yusuf Kebapcı
Institution: Pamukkale University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,630
OpenAlex ID: W7204075870