Investigation of structural, elastic, electronic, and optical properties of lead-free double perovskites Cs 2 XBeBr 6 (X = Ge, Sn): a first-principles DFT study
In this study, the structural, elastic, electronic, and optical properties of Cs GeBeBr and Cs SnBeBr halide double perovskites (HDPs) were investigated using density functional theory (DFT) calculations. Notably, the Tran-Blaha modified Becke-Johnson (TB-mBJ) method was employed to predict indirect...
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Published in | Journal of molecular modeling Vol. 30; no. 10; p. 354 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Germany
29.09.2024
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Subjects | |
Online Access | Get full text |
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Summary: | In this study, the structural, elastic, electronic, and optical properties of Cs
GeBeBr
and Cs
SnBeBr
halide double perovskites (HDPs) were investigated using density functional theory (DFT) calculations. Notably, the Tran-Blaha modified Becke-Johnson (TB-mBJ) method was employed to predict indirect band gaps of 2.434 eV for Cs
GeBeBr
and 2.855 eV for Cs
SnBeBr
. The stability of these compounds in a cubic (Fm-3m) structure was confirmed through formation energy, cohesive energy, tolerance factor, and elastic constants. Furthermore, the ductile nature of the materials was demonstrated through Poisson's and Pugh's ratios. Our optical property analysis, spanning the 0-13 eV energy range, revealed key insights into the dielectric functions, extinction coefficient, electron energy loss, refractive index, optical conductivity, reflectivity, and absorption coefficient. These results highlight the potential of Cs
GeBeBr
and Cs
SnBeBr
for future optoelectronic and photovoltaic applications.
In this investigation, we employed density functional theory (DFT), implemented using the Wien2k package. The exchange and correlation potentials were treated using the generalized gradient approximation (GGA) and the Tran-Blaha modified Becke-Johnson (TB-mBJ) method. To evaluate dynamic stability, we analyzed the phonon band structures using the CASTEP code. |
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ISSN: | 0948-5023 |