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Abstract Halide perovskites are an intriguing renewable energy materials that may assist in addressing the world’s energy scarcity. The Goldsmith tolerance factor (0.99 and 1.00) and negative formation energy guarantee the examined materials’ structural and thermodynamic stabilities. The Poisson’s and Pugh’s ratio proves the reviewed materials’ ductile nature. K/RbOsCl3 has electronic band gaps of 1.37 eV/1.39 eV and the highest light absorption in the ultraviolet and visible areas, enhancing its efficacy for solar cells and other optoelectronics technologies. The highest Seebeck coefficient and electrical conductivity render these materials feasible for thermoelectric properties. KOsCl3 and RbOsCl3 exemplify figures of merit of 0.89 and 0.88, respectively, at the ambient temperature. Additionally, the Debye model was implemented to figure out thermodynamic parameters such as heat capacity, thermal expansion, Debye temperature, and Grüneisen parameter.

Abstract The Electronic and optical properties of InGeX3(X = Cl, Br) were examined by adopting the density functional theory (DFT) approach. We applied the GGA + Trans-Blaha modified Becke–Johnson (TB-mBJ) technique to acquire the precise bandgap of 1.52 and 0.98 eV of the compounds InGeX3(X = Cl, Br) respectively which suggests the direct bandgap at (M-M). The stability of the material is confirmed by the formation energy (– 2.83 = Cl; – 2.35 = Br) and Mechanical stability. Primarily elastic constants were extracted for each of the materials under scrutiny, and these values then served to gauge all of the materials’ mechanical properties. The assessed Poisson’s and Pugh’s ratios for the materials InGeCl3 and InGeBr3 were verified to identify the degree of ductility. The quasi-harmonic Debye model additionally covers the temperature and pressure dependence on thermodynamic parameters, particularly volume, specific heat capacity (Cv) at constant volume, and the Gruneisen parameter (γ) in the range of 0–800 K and 0–5 GPa. It is anticipated that InGeCl3 and InGeBr3 will have static dielectric constants of 4.01 and 5.74, respectively. InGeX3(X = Cl, Br) also reveals significant absorption in the high UV spectrum. The thermoelectric properties have also been calculated vdata-element-id="9QNfR3VHbcMHX_W0fJCYp" data-element-type="html" style="display: initial; visibility: initial; opacity: initial; clip-path: initial; position: relative; float: left; top: 0px; left: 0px; z-index: 1 !important; pointer-events: none;" />ia boltztrap2 code using a k mesh of around 1,50,000 points.

Abstract The present work employs density functional theory to explore the structural, optoelectronic, and thermoelectric attributes of the halide-based double perovskite A2GeSnF6 (A = K, Rb, and Cs) compounds. The stable phonon dispersion spectrum affirms dynamical stability, whereas the enthalpy of formation and tolerance factor evaluated collectively verify structural stability. Considering the Tran Blaha modified Becke Johnson potentials (mBJ), the predicted direct band gaps along the symmetry point are 3.19 eV for K2GeSnF6, 3.16 eV for Rb2GeSnF6 and 3.12 eV Cs2GeSnF6. According to an in-depth examination of the optoelectronic features, A2GeSnF6 (A = K, Rb, and Cs), double perovskites are assuring contenders for optoelectronic devices due to their suitable bandgap. The extremely high figure of merit values (0.94–0.97) obtained from the numerical calculation of power factor and thermal conductivity suggest the intriguing prospects of these compositions for thermoelectric devices. These studies offer a perceptive comprehension of the materials for their potential applications in the future.

Abstract The structural stability, optoelectronic and magnetic characteristics of K2NaMI6 (M = Mn, Co, and Ni) halide double perovskites have been demonstrated to be explained using density functional theory computations. The prominent generalized gradient approximation and integration of the mBJ potential are implemented to estimate the exchange–correlation potential, which is the only unidentified parameter in the state-of-the-art formulism. The structural optimization, mechanical stability criteria, and tolerance factor demonstrate the reliability of the double perovskites in a cubic structure with Fm3m symmetry. The elastic constants facilitated mechanical stability and revealed the brittle nature of these double perovskites. The spin-polarized electronic band profile and the behaviour of the dielectric constant and absorption coefficient in the spin-up and down channels show the presence of half-metallic nature in these materials. Additionally, we examined magnetism and the genesis of the half-metallic gap in this article. The half-metallic and magnetic properties are attributed to the unpaired electrons in the split d-orbitals of the M-sited elements in the crystal field. The Mn-, Co-, and Ni-based double perovskites were found to possess total magnetic moments of 4 μB, 4 μB, and 1 μB, respectively, with the transition metal atoms comprising up the majority of this magnetic moment. The Fermi level’s perfect spin polarisation promotes the potential application of double perovskites in spintronic technology.