https://doi.org/10.1140/epjb/s10051-025-01079-x
Research - Condensed Matter
Investigation of the high-pressure effects on the electronic structure and dielectric properties of CsF: a first-principles study
1
The National Higher School of Hydraulics, 29 Route de Soumaâ, Blida, Algeria
2
Laboratoire d’Etudes Physico-Chimiques des Matériaux (LEPCM), University of Batna 1, 05000, Batna, Algeria
3
Laboratory of Theoretical Computational Chemistry and Photonics, Faculty of Chemistry, USTHB, BP 32, El-Alia, Bab Ezzouar, 16111, Algiers, Algeria
4
Laboratory of Storage and Valorization of Renewable Energies, Faculty of Chemistry, USTHB, B.P. 32, El-Alia, Bab Ezzouar, 16111, Algiers, Algeria
5
Laboratory of Automation and Manufacturing Engineering (LAP), University of Batna 2, 05000, Batna, Algeria
Received:
28
July
2025
Accepted:
18
October
2025
Published online:
5
November
2025
Cesium fluoride (CsF), a prototypical ionic compound with a wide band gap, is of pivotal importance for numerous technological applications. However, its large band gap hinders its functional integration into optoelectronic devices requiring semiconductor properties. The aim of this work is to present a first-principles investigation of the structural, electronic, and dielectric properties of cubic CsF under hydrostatic pressure, using density functional theory within the generalized gradient approximation. Our findings demonstrate a progressive reduction of the band gap from 5.41 eV at ambient conditions to 2.40 eV at 105 GPa, associated with a transition from an indirect gap at zero pressure to a direct gap at high pressure. Analysis of the density of states reveals enhanced s–p hybridization between Cs 6s, and F 2p orbitals under compression, which drives the electronic evolution. In parallel, we observe a significant alteration of the dielectric properties with pressure. The Born effective charges and the electronic part of the dielectric tensor increase monotonically under compression, whereas the ionic part first decreases and then the trend reverses and grows slowly beyond 25 GPa, reflecting complex changes in lattice dynamics. These outcomes provide new insights into the pressure-dependent behavior of CsF and elucidate the potential of external compression as a tool to tune its electronic and dielectric properties for emerging functional applications.
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© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
