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Double perovskites have harvested considerable attention in the realm of solar cells and renewable energy applications. Therefore, in this current study, we explored the structural, electronic, and optical properties of Rb2InGaCl6 and Rb2InGaF6 using DFT-based simulations with WIEN2K codes. It is unequivocally established that both compounds demonstrate structural and mechanical stability. Structural stability is further evaluated using Goldsmith's tolerance factor (τG). The τG values of 4.29 and 3.77 are considered acceptable for ensuring the stability of cubic structures for Rb2InGaCl6 and Rb2InGaF6 respectively. It is determined that both compounds are stable elastically and possess ductile characteristics, allowing them to undergo plastic deformation without fracturing. Our investigation reveals indirect band gaps of 1.7 eV (semiconductor) for Rb2InGaCl6 and 4.8 eV (insulator) for Rb2InGaF6. These diverse band structures open up exciting possibilities for optoelectronic applications. Regarding optical properties, the spectral curves of various parameters are examined in the range of 0 eV to 15 eV incident photon energy. The findings reveal the exceptional optical performance of Rb2InGaCl6 and Rb2InGaF6, particularly by their notably high absorption coefficients α(ω). Specifically, Rb2InGaCl6 demonstrates a remarkable absorption of 6.635 at 2.05 eV, while Rb2InGaF6 exhibits a significant absorption of 3.91 at 4.78 eV. The optical conductivity σ(ω) attains peak values, reaching 4.60 for Rb2InGaCl6 and 2.85 for Rb2InGaF6. Furthermore, the optical reflectivity R(ω) peaks at 13.60 eV for Rb2InGaCl6 and 6.30 eV for Rb2InGaF6. Lastly, the energy loss functions L(ω) attain their highest values of 0.57 and 7.58 for Rb2InGaCl6 and Rb2InGaF6, respectively. These results collectively emphasize the impressive optical characteristics of these compounds across a range of energy levels. These findings suggest promising potential energy applications for these materials, particularly in influencing electromagnetic radiation within the ultraviolet (UV) spectrum ranges. [ABSTRACT FROM AUTHOR]

First-principles calculations using Density Functional Theory (DFT) and the Wien2k package are used to analyze the structural, electrical, optical, and elastic characteristics of Li-based chloride perovskites LiXCl3 (X = Ca, Ba). The structural analysis demonstrates that these compounds are stable and have the space group pm-3m (no. 221). The calculations show that these materials possess an indirect band gap. For elastic properties, the Pugh's ratio (compound ductility), elastic constants, anisotropy factor, Poisson's ratio, and bulk modulus are analyzed. In 0–30 eV energy range, optical parameters such as dielectric function, extinction coefficient, reflectivity, absorption coefficient, refractive index, and optical conductivity, are measured. Optical properties, i.e. dielectric function, extinction coefficient, refractive index, absorption coefficient, reflectivity and optical conductivity, are evaluated in 0–30 eV energy range. The calculations show that these materials possess large band gap and are structurally anisotropic, making these better candidates for scintillator applications. [ABSTRACT FROM AUTHOR]

The basic structural, optical, elastic, and electronic properties are investigated in this research for QZnCl3 (Q = Li and Na) ternary centrosymmetric chloroperovskites compounds utilizing the DFT approach. The integrated TB-mBJ exchange–correlation potential within the WIEN2K computational simulation package serves for precise outcomes. The structural optimization is done by fitting the Birch-Murnaghan equation of state (EOS) for the primitive unit cell energy versus primitive unit cell volume. The parameters from the optimized fitted curves, Goldsmith's tolerance factor (tG), and octahedral coefficient predict the stable cubic structure of QZnCl3 (Q = Li and Na) centrosymmetric ternary chloroperovskites compounds. The elastic parameters which include cubic elastic constants (ECs), elastic moduli (E), Poisson's ratio (v), anisotropy factor (A), and the Pugh ratio (B/G) investigated through IRelast code display the mechanical stability, ductility, and toughness of interested centrosymmetric compounds. Predicted electronic band structures and densities of states (DOS) display that LiZnCl3 and NaZnCl3 possess an indirect (R-Γ) band gap of 3.82 eV and of 3.91 eV respectively, confirming that both the materials are wide band gap semiconductors. In optical properties, the spectral curves of several parameters are observed from 0 eV up to 15 eV incident photons energy, and it is revealed that the centrosymmetric chloroperovskites QZnCl3 (Q = Li and Na) are optically effective at high absorption coefficients (α(ω)), optical conductivity (σ(ω)), optical reflectivity (R(ω)), and energy loss (L(ω)) functions. The potential energy applications can be deemed for these materials, influencing electromagnetic radiation in the ultraviolet (UV) spectrum ranges. In a nutshell, the research on QZnCl3 (Q = Li and Na) demonstrate that these centrosymmetric materials are noteworthy and can be applied as energy storage systems, scintillators, and many other components of present electronic devices. [ABSTRACT FROM AUTHOR]

This study examined the potential consequences of doping on Sr2YGaX2O7(X = Fe, Rh) photovoltaic properties. Density functional theory (DFT) was used to calculate pyrochlore oxides' energy band structure and optical characteristics using the full potential linearized augmented plane wave (FP-LAPW) method. The generalized gradient approximation (GGA + U) was utilized to treat the exchange and correlation potential. We studied the metallic atoms Fe, Rh, Y, and Ga orbital electronic states. The utilization of the complex dielectric function facilitated the computation of various optical properties such as the energy band dispersion statistics, absorption coefficient, reflectivity, energy loss function, refractive index, extinction coefficient, and real optical conductivity parameters. We employed Boltzmann transport theory to delve deeper into the electrical transport characteristics (specifically thermoelectric properties) of Fe and Rh-doped pyrochlore oxides in the temperature range of 0–800 K. It is observed that the Sr2YGaRh2O7 compound indicated higher values of ZT 0.9, 1.25 for 50 K and 800 K, respectively. Further, both the compounds exhibit p-type nature as their seebeck coefficient shows a positive region between 50 and 800 K. The materials with strong thermoelectric properties are assumed in high reflectivity zone and potentially effective in solar heating. [ABSTRACT FROM AUTHOR]

Metal halide perovskites have gained prominence in optoelectronics recently, thanks to their unique optical and electrical properties, along with their adaptable morphologies. The current work reports the electronic, structural, mechanical, optical, and thermoelectric traits of Rb2TlInBr6 for the very first time. The confirmation of thermodynamic stability is evidenced by the negative value of the formation energy, while structural stability is established by calculating values for the tolerance factor and octahedral tilting. Elastic constants (Cij) and mechanical attributes are evaluated to assess perovskites' ability to resist external strains. Electronic band structures computed with GGA and mBJ potentials depict a semiconducting nature containing indirect bandgap of 1.8 and 2.42 eV, respectively. Optical characteristics of Rb2TlInBr6 ensure that it can be used effectively for optoelectronic applications. An insight into the thermoelectric characteristic is assessed through BoltzTraP code. The electrical conductivity and ZT reveal the ability of Rb2TlInBr6 to be utilized in green energy devices. [ABSTRACT FROM AUTHOR]

To improve the performance of materials, we employ first-principles techniques based on density functional theory (DFT) implemented in the Wien 2k code to study perovskites Ba3CaAx2O9. We used the Birch-Murnaghan fit, tolerance factor, and formation energy to determine the structural stability of these materials. Structurally stable compounds Ba3CaAx2O9 have a tolerance factor of 0.7, 1.1, and 0.9, respectively, and a formation energy of −3.04 eV, −1.98, and −1.12 eV. We used the proposed mBJ+U potential to assess the properties of the present materials, providing insight into their nature. Band gaps of 1.5–3.2 eV for Ba3CaAx2O9 (Ax = Nb, Mo, Rh) indicate that they are indirect semiconductors. We also calculate the density of states (DOS) for both materials, and our results for the energies of the band gaps agree with those from the band structure. Absorption and optical conduction are observed to occur in the UV region, and all investigated materials are transparent to low-energy photons. Our investigation into the optical characteristics of these materials suggests they could be promising candidates for application in optoelectronic devices. Finally, the Seebeck coefficient, electrical conductivity, thermal conductivity, power factor, and figure of merit have been calculated to investigate the thermoelectric efficiency of the triple perovskites based on semi-classical Boltzmann theory. The findings suggest that triple perovskites may be a promising candidate for optoelectronic and thermoelectric applications. [ABSTRACT FROM AUTHOR]

Fluoroperovskites, a subgroup of perovskite materials, have gained substantial scientific interest due to their outstanding optoelectronic properties and potential applications in electronic devices, such as solar cells, LEDs, and transistors. These unique properties originate from the crystal structure, enabling adaptable bandgap engineering. This paper investigates the structural, elastic, electronic, and optical properties of LiXF3 (X = Cd, Hg) using Density Functional Theory in WIEN2K. The stable cubic nature of LiCdF3 and LiHgF3 with lattice constants of 4.396 Å and 4.560 Å, respectively, is revealed. Elastic property analysis confirms mechanical equilibrium and ductility, while band structure calculations indicate indirect band gaps of 2.64 eV and 3.38 eV for LiCdF3 and LiHgF3, respectively, from (M − Γ). Optical properties within a 15 eV range are correlated with the electronic structure, providing a comprehensive understanding of Li-based fluoroperovskites' physical attributes. [ABSTRACT FROM AUTHOR]

Structural, electronic, magnetic and elastic characteristics of do half-Heusler alloys CsXB (X = Mg and Sr) are investigated by using First-principles study based on density functional theory. Full-potential linearized augmented plane wave method is used to study these compounds in WIEN2k. The generalized gradient approximation that Perdew–Burke–Ernzerhof developed is used to deal with the exchange correlation function. The elastic characteristics have been employed with the IRelast package, which is already included into WIEN2K. Band structure and density of states are used to describe electronic properties which indicate the half-metallic nature of these compounds. Both CsMgB and CsSrB have minimum energies for spin channel. According to our calculations, CsMgB has a gap of 0.44 eV for spin down channel while CsSrB shows a gap of 0.34 eV for spin up channel. These two compounds exhibit half-metallic characteristic with total integer magnetic moment per formula unit, i.e., 2.00002 for CsMgB and 2.00004 µB of CsSrB which is in well accordance with the Slater–Pauling rule [Mtot = (8−Ztot) µB]. Both compounds are mechanically stable and reveal ductile nature. The obtained results reveal that CsSrB and CsMgB compounds are HM ferromagnets with perfect spin polarization in the absence of transition metals which make them promising candidates for spintronic devices. [ABSTRACT FROM AUTHOR]

Double perovskites (DPs) have attracted considerable attention for their potential in optoelectronic and thermoelectric applications. In this study, we utilize the WIEN2K code, which relies on density functional theory, to analyze the structural, electronic, mechanical, and optical properties of X2NaTlF6 (X = Cs, Rb). To assess the material's structural durability, we determine the tolerance factor, and thermodynamic stability is examined through formation energy and phonon calculations. Mechanical stability is confirmed through the relationship between elastic constants, specifically C11 - C12 > 0, C11 > 0, C11 + 2C12 > 0, and B > 0. Furthermore, an analysis of elasticity using the IRelast package reveals their resilience, anisotropic properties, and mechanical stability. The calculated elastic moduli indicate that Rb2NaTlF6 displays ductile behavior, while Cs2NaTlF6 demonstrates brittleness, depending on the specific elastic constant under consideration. Utilizing the modified Beck and Johnson potential (TB-mBJ), we determine band gaps of 1.23 eV for Rb2NaTlF6 and 1.64 eV for Cs2NaTlF6 DPs. Additionally, we investigate optical properties, including refractive index, dielectric constant, and reflectivity, providing further insights into their behavior. Optical property calculations for both compounds suggest their potential suitability for use in optoelectronic devices, particularly LEDs, owing to their UV-Vis range absorption characteristics. [ABSTRACT FROM AUTHOR]

In this study, first-principles numerical computations for zinc-blende ternary alloys (In1−xAlxSb) are performed concerning elastic, structural, electronic, thermal, and optical properties. This study is carried out using the "full-potential linearized augmented-plane-wave plus local-orbital, (FP-L(APW + lo))" approach framed within "density functional theory" and realized in the WIEN2k computational package. From our computational work, performed at the level of generalized gradient approximation suggested by Wu and Cohen (GGA-WC) for the exchange–correlation functional, we see that our obtained results for the structural parameters of the title alloys (In1−xAlxSb) are increasing with increasing concentration x, and by and large, follow the Vegard's law. To predict reliable electronic and optical properties "Tran–Blaha modified Becke–Johnson (mBJ)" potential approach was employed. We note, except at x = 1 and x = 0.75, electronic band gaps are of direct nature for evaluated concentrations of the title alloys. In addition, noticeable variation is noted in the optical parameters with x concentration. For analyzing the thermal character of the title alloys, the "quasi-harmonic Debye model" scheme is used. Comparison of obtained results with experimental and predicted ones is found in good agreement where available. Hence our computational study of the title alloys endorses the reliability of our investigations and might offer a valuable platform for future predictions and experimental work as well as suggest that title material is the best candidate for optoelectronics. The optical quantities obtained using mBJ show low energy loss and reflectivity and high absorption capability in the infrared and visible regions for In1−xAlxSb, making these materials potential candidates in solar cell applications. [ABSTRACT FROM AUTHOR]

This research paper presents a thorough investigation of the structural, elastic, electronic, and optical properties of AuXF3 (X = Ca, Sr) compounds using density functional theory (DFT). The study utilizes the WEIN2K software, enabling the determination of various material characteristics. The analysis reveals that both AuCaF3 and AuSrF3 exhibit stable and cubic structures, as evidenced by Birch Murnaghan curve optimization, with computed lattice constants of 4.4270 Å and 4.7191 Å, respectively. The evaluation of elastic properties, including elastic constants, Young's moduli, anisotropy factors, Poisson's ratios, bulk moduli, and Pugh's ratios, indicate that both compounds possess ductile behavior, show anisotropy, and display mechanical stability. Furthermore, band structure calculations demonstrate wide indirect energy band gaps of 3.11 eV (M-Γ) for AuCaF3 and 3.35 eV (M-Γ) for AuSrF3, suggesting their semiconducting nature. An in-depth analysis of the partial and total density of states provides insights into the contributions of different elemental states to the band structure. The investigation of optical characteristics within the energy range of 0 eV to 15 eV encompasses refractive indices, absorption coefficients, and reflectivity. The compounds exhibit notable optical properties at higher energies, indicating potential applications such as energy storage and high-energy applications. Overall, this research offers a comprehensive computational analysis of AuXF3 (X = Ca, Sr) compounds, shedding light on their structural, elastic, electronic, and optical properties, and presenting opportunities for energy storage and high-energy applications. [ABSTRACT FROM AUTHOR]

DFT study on the structural, optoelectronic, thermodynamic, vibrational, and mechanical properties of Ruddlesden Popper (RP) perovskites Sr2XO4 (X = Zr, Hf) is made with the help of first principle simulation in the framework of WIEN2K code. The lattice constants in bohr unit are found to be a=7.313,b=7.313,c=23.346 for Sr2ZrO4, and a=7.310,b=7.310,andc=23.368 for Sr2HfO4. The calculated band gap values are 2.65 eV for Sr2ZrO4 and 2.58 eV for Sr2HfO4. The band structure and electronic density of states reveal the semiconductor nature of these materials having an indirect band gap. Also, Kramers–Krönig relations are used for optical analysis which unveils that these compounds are suitable for applications in optoelectronic. The vibrational investigations are done while using harmonic approximation. Phonon dispersion curves are plotted to observe the vibrational modes by DFPT to confirm the dynamical stability of studied compounds. Although few soft modes have appeared, however, these compounds are found to be thermally stable. Raman modes appeared at low and high frequencies whereas IR modes are noticed at intermediate frequencies for considered compounds. Upon thermodynamical examination, the maximum value of free energy at 1000 K is noted to be −1.95 eV for Sr2ZrO4 and −2.25 eV for Sr2HfO4. The elastic constants are calculated by using the Voigt–Reuss–Hill approximation. The calculated anisotropic values for these compounds are 1.077 (A) and 0.913 (A) which indicate that Sr2ZrO4 has isotropic behavior and Sr2HfO4 has anisotropic behavior. From our calculations, Voigt Young's modulus of Sr2ZrO4 and Sr2HfO4 is 266.99 (GPa) and 279.42 (GPa) along with Poison's ratio of 0.29 and 0.26, respectively. [ABSTRACT FROM AUTHOR]

Context: We comparatively investigate the properties of pure ZnO and 2 at. % Al doping concentration of ZnO, AZO, as potential candidates for specific applications. Methods: Calculations were carried out, using Wien2k package, to deduce structural, electronic, optical thermoelectric, and properties of both ZnO and AZO materials via the combination of GGA and mBJ approximations. Results: It is shown that Al doping of ZnO (AZO) improves its optical properties; the deduced direct fundamental gap is enhanced due to the Burstein–Moss effect. Moreover, the dielectric function, at lower energies, confirms the existence of an extra strong fluctuation in the dispersive real part ɛ1(ω) and a high peak for absorptive imaginary parts ɛ2(ω) which are due to a variation in specific molecular bonding and the transition between the occupied and the non-occupied states. The critical point, observed at 2.81 eV for pure ZnO, is shifted to 3.3 eV in 2 at. % AZO, confirming a larger optical band gap. The reflectivity values slightly decreased for 2% AZO. The investigation of thermoelectric parameters as a function of chemical potential at different temperatures ranging from 300 to 900°C showed that these structures can be considered for good thermoelectric devices with (i) high absolute values of Seebeck coefficient: ׀SZnO׀ = 1.16 mV/K and ׀SAZO׀ = 0.746 mV/K, (ii) no effect of temperature on electrical conductivity but a strong effect on thermal conductivity, (iii) a high value approaching unity for the figure of merit. Hence, these properties and their improvements, introduced by Al doping of ZnO, lead specific and more uses in optoelectronics, energy, and piezoelectric applications. [ABSTRACT FROM AUTHOR]

Perovskite solar cells are the future of energy production due to the high- efficiency and low production costs. In this work, the structural, electronic and optical properties of the tetragonal inorganic halideperovskiteRbSeBr3 are performed using the full potential linearized augmented plane waves (FP-LAPW) method with the PerdewBurke–Ernzerh generalized gradient approximation (PBE-GGA) as well as the local density approximation (LDA) and the modified Becke-Johnson (mBJ-LDA) as exchange correlation potentials using Wien2k code. Furthermore, the thermoelectric propertieshave been calculated using BoltzTrap code, the obtained results show that the studied compound (RbSeBr3) has a metallic character and can be used as an absorber in UV-interval; on the other hand the thermoelectric power reveals a high value.

Thermoelectric materials have widely used applications in technological areas such as electronic devices and data storage. TlInSe2 and TlInTe2 compounds are among these thermoelectric materials. In this study, while the structural, electronic, and optical properties of TlInSe2, TlInTe2, Tl0.75Na0.25InSe2 and Tl0.75Na0.25InTe2 compounds have been examined with the WIEN2k program based on DFT, their thermoelectric properties have been calculated with another program BoltzTrap. The electronic calculations show that, all compounds exhibit indirect band gap properties. In addition, the band gap energy of Tl0.75Na0.25InSe2 is shifted in the electromagnetic spectrum. The optical properties are found to change depending on the direction for all compounds. Finally, the thermoelectric parameters have been calculated depending on temperature. It is thought that especially the results for Na-doped compounds will be a leading reference for experimental studies.

This study is aimed at exploring the electronic, magnetic, and magneto-optical properties of double perovskites Ca2FeIrO6 and Ca2CoIrO6 with monoclinic structure (space group P21/𝑐) in order to examine their potential applications in spintronic and photovoltaic devices. The calculations were done using the full-potential linearized augmented plane wave within the density functional theory. For the electronic exchange-correlation function, we used the generalized gradient approximation (GGA) and GGA+U (Hubbard potential), and spinorbit coupling (SOC). The study showed that Ca2FeIrO6 and Ca2CoIrO6 exhibit a monoclinic structure (space group P21/𝑐). The structure relaxation shows an antiferromagnetic behavior in both systems with a magnetic moment of about 6.00𝜇𝐵 for Ca2FeIrO6 and 4.00𝜇𝐵 for Ca2CoIrO6 by using GGA+U approximation. The results of GGA and GGA+U predict the half-metallic behavior of Ca2FeIrO6 and Ca2CoIrO6. The magneto-optical polar Kerr effect (MOKE) was examined by studying the variation of Kerr and ellipticity rotation. The Kerr rotation angle is 1.3◦ at 4.82 eV and -1.21◦ at 4.3 eV, and the ellipticity angle is -1.21◦ at 4.3 eV for Ca2FeIrO6. In the case of Ca2CoIrO6, the Kerr rotation angle is -1.04◦ at 4.05 eV; the significant Kerr rotation in both compounds may suggest the application of these materials in optoelectronics bias. The named compounds have a potential application in the field of spintronics and its devices, such as in optoelectronics technologies. [ABSTRACT FROM AUTHOR]

This work describes the optimization of photovoltaic parameters of the inorganic perovskite solar cell (PSC) with RbGeX3 (X = I, Br, Cl) as the absorber layer, employing the DFT based absorption spectrum and band gap estimated with the help of WIEN2k software. For analysing the PSC using SCAPS 1D tool, IGZO and Cu2O are incorporated as the electron transporting layer and hole transporting layer respectively. Using Au as metal at the back electrode, the device configuration exhibits a peak PCE of 13.79% for RbGeI3 based PSC when the SCAPS conventional absorption spectrum for RbGeI3 is used for the study. However, when absorption spectrum obtained by DFT principles is employed for RbGeI3, device configuration exhibits a PCE of 6.49%. Our study shows that the absorption spectrum generated by DFT calculations is more reliable and accurate as it incorporates minute variations of absorption with quantum mechanical level of accuracy for different wavelengths of the incident light. When the halide ion I− of the perovskite structure, RbGeI3 is replaced by Br− or Cl−, the device configurations exhibited PCE values of 10.09% and 3.69% respectively with SCAPS default absorption spectrum, mainly due to the increase in bandgap of the resulting perovskite structures, RbGeBr3 and RbGeCl3 while a PCE of 2.87% and 1.48% are achieved for device configurations with DFT absorption spectra of RbGeBr3 and RbGeCl3 respectively. [ABSTRACT FROM AUTHOR]

The implementation of a density functional theory framework, specifically the full potential linearized augmented plane wave method, has been utilized to predict the electronic, structural, magnetic, and optical properties of Cs2LiCeBr6, a scintillating bromo-elpasolite material. The optimized lattice parameter "ao" is reported to be in reasonable accordance with the experimental value, and the lowest energy in the spin-polarized approach is observed. As per the Tran and Blaha modified Becke-Johnson potential approximation, the optimized results reveal that the band gap of the material is indirect at the momentum points from Γ-X. The calculated values for the band gap in the spin-up and down channels are 2.77 eV and 3.12 eV, respectively. The verification of ferromagnetic behavior is confirmed by the asymmetric densities of states in both spin schemes. Furthermore, based on the values of the band gap, the substance is classified as a ferromagnetic semiconductor. The optical properties are analyzed within the energy range spanning from 0 eV to 20 eV, and the Perdew-Burke-Ernzerhof generalized gradient approximation and the Tran and Blaha modified Becke-Johnson approximations are compared. The material being investigated demonstrates valuable characteristics, including absorption in the extreme ultraviolet range, reduced reflectivity, and elevated optical conductivity values. These properties make it suitable for various applications, including radiation detection in particle physics, medical instrument construction, security applications, and high-frequency devices that rely on ultraviolet radiation. [ABSTRACT FROM AUTHOR]

The implementation of a density functional theory framework, specifically the full potential linearized augmented plane wave method, has been utilized to predict the electronic, structural, magnetic, and optical properties of Cs2LiCeBr6, a scintillating bromo-elpasolite material. The optimized lattice parameter "ao" is reported to be in reasonable accordance with the experimental value, and the lowest energy in the spin-polarized approach is observed. As per the Tran and Blaha modified Becke-Johnson potential approximation, the optimized results reveal that the band gap of the material is indirect at the momentum points from Γ-X. The calculated values for the band gap in the spin-up and down channels are 2.77 eV and 3.12 eV, respectively. The verification of ferromagnetic behavior is confirmed by the asymmetric densities of states in both spin schemes. Furthermore, based on the values of the band gap, the substance is classified as a ferromagnetic semiconductor. The optical properties are analyzed within the energy range spanning from 0 eV to 20 eV, and the Perdew-Burke-Ernzerhof generalized gradient approximation and the Tran and Blaha modified Becke-Johnson approximations are compared. The material being investigated demonstrates valuable characteristics, including absorption in the extreme ultraviolet range, reduced reflectivity, and elevated optical conductivity values. These properties make it suitable for various applications, including radiation detection in particle physics, medical instrument construction, security applications, and high-frequency devices that rely on ultraviolet radiation. [ABSTRACT FROM AUTHOR]

The purpose of this study is to conduct theoretical investigations on the electronic, structural and magnetic properties of lithium niobate (LiNbO3) doped with different concentrations of the transition metal chromium (Cr). All properties of LiNb1−xCrxO3 compounds (x = 0.25, 0.50 and 0.75) are achieved with spin-polarized density functional theory by the GGA-PBE and the TB-mBJ approximations. To ensure the stability of the LiNb1−xCrxO3 quaternary alloy in the ferromagnetic state, the total energy released from the optimized structure and the defect formation energy were calculated. The classical Heisenberg model estimated the Curie temperature of the compounds. The material studied exhibits a 100% spin-polarized semi-metallic ferromagnetism behaviour. In all compounds, the data of the magnetic moment demonstrated that the chromium impurity atom is the most important source by comparison with the Nb and Li, which have minor contributions. In addition, the magnetic moment of the Cr atoms decreases with doping; this comes from the p–d hybridization between the Cr-3d and O-2p states. The half-metal gap (GHM), the most important factor in spintronics applications, was also calculated. In addition, to assess the effects of the exchange separation process, the crystal field separation energy, the exchange separation parameters, and the exchange constants N0α, N0β, and ΔEC, ΔEV are predicted. [ABSTRACT FROM AUTHOR]

Renewable energy prices are decreasing, making it easier to make energy systems that are good for the environment. High-density storage for renewable energy is possible with hydrogen. This work focuses on the theoretical study of LiXH3 (where X = Ti, Mn, and Cu), including their structural, electronic, mechanical, thermoelectric, and hydrogen storage properties, using first-principles calculations. LiCuH3 is more stable than LiMnH3 and LiTiH3, based on the optimization graph. The electronic properties show the metallic nature of these studied hydrides. Born's criterion indicates that all studied hydrides are brittle for various mechanical applications. LiTiH3, LiMnH3, and LiCuH3 are all thought to be able to store hydrogen with gravimetric storage capacities of 5.22%, 4.66%, and 4.11%, respectively. Based on how their thermoelectric properties change with temperature, all the materials under study can absorb heat energy, which shows that they are both electrically and thermally conductive. [ABSTRACT FROM AUTHOR]

In this study, the investigations of structural, electronic, optical, and magnetic properties of a scintillating double perovskite halide (Cs2LiCeCl6) by using the full-potential linearized augmented plane wave (FP-LAPW) method in the framework of density functional theory (DFT) is reported. The optimized lattice constant (a0) is fully consistent with the experimental results, and the ground state optimized energy confirms the cubic (Fm 3¯ m space group) stability of the compound. The electronic band structures and densities of states are analyzed within approximations of PBE-GGA and TB-mBJ to have precise and accurate results. In the spin-up channel the metallic behavior of the compound is confirmed, while in the spin-down channel there is a band gap of 3.83 eV with an indirect nature from Γ-X, so clarifying its behavior towards semiconductors and thus overall making the compound to be half-metallic, and hence, it is clear that the material exhibit spin polarization. The ferromagnetic behavior is verified by the asymmetric density of states in both spin channels and the optimized energy volume curve in spin-polarized calculations. The optical parameters are computed and it is found that the compound Cs2LiCeCl6 possesses high optical conductivity, absorption coefficient and compared in both approximations and analyzed in the energy range of (0–20) eV and hence predict the applications of this material in high-frequency ultraviolet devices and also for particle detection.

Herein the first-principle modeling within the DFT framework is used to investigate the structural, optoelectronic, elastic, and thermoelectric properties of BaMF3 (M = Ag and Cu) ternary halide Perovskites compounds. The computed tolerance factors for BaAgF3 and BaCuF3 are 0.919 and 0.991 respectively, indicating that the cubic crystal phase of these selected compounds is thermodynamically and mechanically stable. It is found that both the compounds are structurally stable according to the Birch-Murnaghan fit curve for optimization. The IRelast package is used for investigating the elastic properties of both cubic compounds and the findings show that these compounds are mechanically stable, scratch-resistant, ductile, anisotropic, and resistant to plastic deformation. The Trans-Blaha modified Becke-Johnson (TB-mBJ) approximation is employed to determine electronic properties with accuracy and precision. The electronic-band structure analysis depicts a narrow band gap semiconductor nature of BaAgF3 and BaCuF3 compounds which displays indirect band gaps of 0.2 eV for BaAgF3 and 0.3 eV for BaCuF3 at the high symmetrical points from (Γ–M). Furthermore, the computations of total densities of states (TDOS) and partial densities of states (PDOS) are carried out to determine how different states contribute to the various band structures. The optical characteristics of BaAgF3 and BaCuF3 are comprehensively examined in 0–40 eV energy ranges. The selected materials possess high optical conduction and absorption coefficients at the high level of photon energies and show transparency at low incident photon energy ranges. The investigations of optical properties led us to the conclusion that BaAgF3 and BaCuF3 are suitable to use in high-frequency UV devices. The thermoelectric properties show that both materials hold high-power factors, electrical conductivity, and figures of merit (ZT), indicating that they are good thermoelectric materials. This is the first theoretical computational systematic analysis of structural, optoelectronic, elastic, and thermoelectric properties of BaMF3 (M = Ag and Cu) that will be experimentally validated to our knowledge.

Motivated by solar energy activities, we investigate X 2 ZnGeS 4 (X = Ba, Mg, Sr) semi-conductors using the density functional theory (DFT) calculations implemented in WIEN2K package and Boltzmann theory with the BoltzTraP code. Precisely, we study the electronic, the optical and the thermoelectric properties of such a family of materials using the generalized gradient approximation corrected by the Tran Balaha modified Becke-Johnson exchange potential (GGA+ TB-mBJ) scenarios. We first approach the electronic band structure which shows that the proposed materials involve an indirect band gap. Then, we discus the associated optical aspect by computing the relevant quantities including the absorption coefficient in terms of the energy function. By the help of the BoltzTraP code via the Boltzmann theory, we examine the thermoelectric properties. More precisely, we investigate the Seebeck coefficient, the thermal conductivity, the electrical conductivity, the thermoelectric power factor, and the figure of merit as functions of the chemical potential at different temperatures. Among others, we find a high absorption spectra and a good figure of merit (ZT) suggesting that such materials could be exploited for photovoltaic and thermoelectric applications. [ABSTRACT FROM AUTHOR]

The formation of the Ti substituted Mg 2 Ni alloys, a promising hydrogen storage material for various applications is studied in detail. Mg 1.95 Ti 0.05 Ni alloy and ribbons are successfully prepared by vacuum arc melting and melt spinning methods. The phases, microstructures, and thermal behavior of the alloys and ribbons are characterized by XRD, SEM, TEM, DTA/TG. Sievert-type apparatus is used to study hydrogen sorption properties. Apart from the dominant Mg 2 Ni phase, the formation of MgNi 2 , Mg, and Ni 3 Ti phases is seen in both Mg 1·95 Ti 0·05 Ni alloy and ribbons. During the initial three cycles, Mg 1·95 Ti 0·05 Ni ribbons showed 2 wt % hydrogen storage capacity. To explain the atomic-scale influence of Ti dopant in the studied alloys and hydrides, FP(L)APW + lo method based on Density Functional Theory (DFT) is applied to Mg 2-x Ti x Ni (x = 0.25 and 0.5) alloys and Mg 2-x Ti x NiH 4 (x = 0.25 and 0.5) hydrides. An increase in the Ti dopant on the Mg site leads to the hydrides destabilization. Bader's charge density topology analysis provides insight into the charge transfer and bonding between the constituent atoms. • Partial substitution of a low amount of Ti was carried out in Mg 2 Ni intermetallic alloy. • The melting temperatures of the intermetallic Mg 2 Ni phases in Mg 1·95 Ti 0·05 Ni alloy and ribbons are about 725 °C. • Hydrogen storage capacity of Mg 1·95 Ti 0·05 Ni ribbons reaches 2 wt% at 350 °C. • Ti reduces the stability of the hydride by weakening the binding energy. [ABSTRACT FROM AUTHOR]

The increasing research of advanced materials with tremendous compositional and structural degrees of variation, identifying and discovering new materials for a specific application is a challenging task. Here, we report for the first time the predicted structural, optoelectronic, and mechanical properties of germanium based AGeF3 (A = Ga and In) halides Perovskites using the density functional theory computational approach. The tolerance factor "τ" is computed for both the materials and is found to be 0.91 for InGeF3 and 0.89 for GaGeF3 which indicates the structural stability of these perovskites crystal structures. The optimized crystal structural parameters for both the compounds are found to be 4.476 Å for InGeF3 and 4.422 Å for GaGeF3 by performing the fit using Birch–Murnaghan for the unit cell energy verses unit cell volume. Using the optimized lattice constants all the basic physical properties are computed. From the results of electronic properties it is determined that both the compounds depict a semiconductor nature with having an indirect (R-M) band gap of 1.48 eV for InGeF3 and 0.98 eV for GaGeF3. To explore the potential of these selected compounds the optical properties within the energy range of 0 eV up to 40 eV incident photon are computed for the prospective optoelectronic applications. Moreover, the mechanical properties for both the materials are computed using the IRelast package and the values of cubic elastic parameters estimates that AGeF3 (A = Ga and In) halides Perovskites are mechanically stable, hard to scratch, ductile and anisotropic. We are fully confident on the precision and accuracy of our reported results and reveals that the applications of germanium based AGeF3 (A = Ga and In) halides Perovskites compounds can be deemed in photovoltaic and in modern semiconducting industries. [ABSTRACT FROM AUTHOR]

Structural, electronic, optical and elastic properties of Silver based Perovskite AgXCl3 (X = Ca, Sr) are studied by utilizing wien2k package with in DFT. The structural investigation reveals their stability and shows that these compounds are cubic with space group pm-3m 221. For electronic properties the band structure and density of states are computed which indicates the semiconducting nature of both compounds. Elastic constants, Pugh’s ratio, bulk modulus, Poisson’s ratio and anisotropy factor are studied for the analysis of elastic characteristic. The Pugh’s ratio describes the ductile nature of the compounds and ionic nature is determined from the evaluated Cauchy pressure. Optical parameters such as dielectric function, extinction coefficient, refractive index, absorption coefficient, reflectivity and optical conductivity are calculated in the energy range of 0 eV–35 eV. The thermal stability is conformed from the thermal property. The study of these compounds reveals that they can be potential candidates for optoelectronic devices.

The half-metallic calculations of new variant perovskites Li2CrO6 and Li2CuO6 were carried out by using WIEN2k computational code. First, the ferromagnetic (FM) and non-magnetic (NM) phases were compared, and FM phases were obtained energetically more stable. The equilibrium lattice constants were obtained as 7.63 Å and 7.66 Å for Li2CrO6 and Li2CuO6, respectively. Second, the electronic calculations were performed, and the semiconduction properties were seen in spin-up states while spin-down states showed metallic nature. The band gaps were obtained as 1.806 eV and 1.177 eV for Li2CrO6 and Li2CuO6, respectively. Since variant perovskites Li2CrO6 and Li2CuO6 showed 100% spin polarizations, these were obtained as true half-metallic ferromagnetic materials. Then the total magnetic moments were obtained as 4.00 μB/f.u., 5.00 μB/f.u. When both the electronic and magnetic properties of the compounds are examined, the variant perovskites Li2CrO6 and Li2CuO6 are suitable materials for spintronics applications. [ABSTRACT FROM AUTHOR]

Various properties of S r 2 M W O 6 (M = V , R h , R u) are investigated based on the DFT theory using the full-potential linearized augmented plane wave (FP-LAPW) method. Their magnetic properties show a half metallic bahavior for M = V and Rh with high magnetic moments. However, for S r 2 R u W O 6 , the bands for up and down spins are symmetric and thus this material is non-magnetic with an energy band gap of 1.4 e V . The presence of Ru and Rh in S r 2 M W O 6 structure increases the absorption of this material, especially in the visible light range. The elastic constants C α β for all studied compounds were obtained using Elastic1.1 and satisfy the Born stability criterion. This indicates that all the compounds are mechanically stable. Finally, electrical properties were determined using BoltzTraP package leading to interesting aspects. The obtained results are comparable with other perovskite phases. Therefore, these coupled features of the title compounds make them promising material for different applications. [ABSTRACT FROM AUTHOR]

In the present paper, structural, electronic, elastic, thermodynamic, optical, and thermoelectric properties of h-H alloys KXSb (X = Be, Mg, Ca, and Sr) are investigated for the first time. These properties were explored using quantum mechanical model – the density functional theory (DFT) with both GGA-PBE and TB-mBJ exchange-correlation functional. The Boltzmann transport equations and the Full Potential Linearized Augmented Plane wave (FP-LAPW) approach, as built into the WIEN2k code, are used to investigate these properties. The band structures and density of states (DOS) are also studied. The half-Heusler compounds show semiconductor properties with both the GGA and mBJ methods, while the KBeSb alloy exhibits metallic nature under the GGA-PBE approach. The elastic and thermo dynamical properties were also investigated, and the results revealed that the compounds are mechanically and thermally stable. The observed high Debye temperature (ϴ D ) implies that the alloy is harder and possesses a significant Debye sound velocity. The current paper highlights the optical and thermoelectric applications of the alloys. At 900 K, KCaSb exhibits maximum power factors of 8.83 × 1011 (W/mK2s) with the GGA-PBE method and 8.19 × 1011 (W/mK2s) with the TB-mBJ approach. • Structural, Electronic, mechanical, optical properties and thermoelectric of KXSb (X = Be, Mg, Ca, Sr) half-Heusler compounds are studied. • The electronic and DOS results reveals that the KBeSb alloy exhibit metallic nature and KXSb (X = Mg, Ca, Sr) shows the semiconducting nature. • The elastic results confirm the mechanical stability of the compounds. • The optical conductivities of compounds are obtained in visible region. • Interestingly, the highest electrical conductivity (σ/τ) of 10.3 × 1019 Scm− 1 s− 1 for KMgSb is obtained at room temperature. [ABSTRACT FROM AUTHOR]

The study investigates the structural, mechanical, optoelectronic, and thermoelectric properties of pure and doped ZrO2 using WIEN2k. The goal is to evaluate their potential contribution to future thermoelectric and photovoltaic systems. Thermodynamic stability is confirmed through molecular dynamic simulations, while mechanical stability is confirmed through mechanical features. The electronic characteristics are determined using the GGA-PBE functional. For pristine, 25 % doped, and 50 % doped ZrO 2 , the measured band gaps were 3.10, 2.92, and 2.73eV, respectively. Significant absorption and conductivity are found in the examined optical properties, together with decreased reflectance and optical loss, which points to a lower rate of electron-hole pair recombination. At lower temperatures, the thermoelectric properties show a noteworthy ZT. As a result, these materials may efficiently transform thermal energy into useful electrical power and offer a considerable potential for optoelectronic technology. • Exploration of metal oxides is important for their potential in optoelectronic and thermoelectric applications. • The Stability of the under study pure and doped ZrO 2 is confirmed through formation energy (E f) and dynamics simulations. • Varying the doping concentration, alter band gaps 3.10-2.73eV, affecting light absorption properties. • The enhanced figure of merit, make these materials suitable for thermoelectric devices. • Potential applications extend to photovoltaic devices due to the high figure of merit at low temperatures. [ABSTRACT FROM AUTHOR]

In this work, the structural, electronic, optical and thermoelectric properties of Cs 2 AlAgBr 6 , K 2 AlAgBr 6 and Rb 2 AlAgBr 6 have been investigated using WIEN2k code. All the three double perovskites show stability. The stability is confirmed by calculating their formation energy, tolerance factor and molecular dynamic simulations. The electronic properties revealed the understudy compounds as semiconductors of direct band gap of 2.62, 2.61 and 2.59 eV for Cs 2 AlAgBr 6 , K 2 AlAgBr 6 and Rb 2 AlAgBr 6 , respectively. The absorption band of our compounds is mostly in the ultraviolet energy range which is particularly significant for optoelectronic devices. The studied double perovskites exhibit a large Seebeck coefficient and electrical conductivity, which is significant for the high figure of merit. These properties make them particularly suitable for thermoelectric (TE) devices and other photovoltaic applications, as their high figure of merit at low temperatures opens up new possibilities for these materials. [ABSTRACT FROM AUTHOR]

The electronic structure analysis reveals semiconducting behavior, with bandgaps of 0.66 eV for Rb 2 AsAuCl 6 and 0.07 eV for Rb 2 AsAuBr 6 , attributed primarily to the interaction between As and Au states near the Fermi level. Optical investigations highlight significant absorption in the visible spectrum with onset edges in the infrared (IR) region in addition to low reflectivity (less than 10 %) and high conductivity makes both HDPs potential contender for their applications in wide range of optoelectronic devices. The thermoelectric analysis reveals promising performance, with figure of merit (ZT) values approaching ∼0.8 for Rb 2 AsAuCl 6 and ∼0.5 for Rb 2 AsAuBr 6 at room temperature. [Display omitted] • The negative Δ H f confirms the stability of Rb 2 AsAuX 6 (X = Cl, Br). • Rb 2 AsAuCl 6 /Rb 2 AsAuBr 6 have E g of 0.66/0.07 eV, correspondingly. • Both compounds have absorption in visible to infrared region. • Rb 2 AsAuCl 6 has maximum ZT value of 0.79. • Investigated compounds are suitable for TE and optoelectronic applications. Herein, we investigated the physical characteristics of two narrow band gap halide double perovskites (HDPs) Rb 2 AsAuX 6 (X = Cl, Br) by using density functional theory (DFT) calculations. Both compounds exhibit thermodynamical stability with non-magnetic ground states and stable cubic symmetry supported by geometry optimization, tolerance factor criteria, and negative formation enthalpies. The electronic structure analysis reveals semiconducting behavior, with bandgaps of 0.66 for Rb 2 AsAuCl 6 and 0.07 eV for Rb 2 AsAuBr 6 , attributed primarily to the interaction between As and Au states near the Fermi level. Optical investigations highlight significant absorption in the visible spectrum with onset edges in the infrared (IR) region in addition to low reflectivity (less than 10 %) and high conductivity makes both HDPs potential contender for optoelectronic device applications across a broad spectrum. The thermoelectric analysis reveals promising efficiency, with figure of merit (ZT) values approaching ∼0.8 for Rb 2 AsAuCl 6 and ∼0.5 for Rb 2 AsAuBr 6 at room temperature. The results indicate that Rb 2 AsAuCl 6 and Rb 2 AsAuBr 6 have the potential to be used in future optoelectronic and thermoelectric applications due to their unique combination of structural stability, tunable bandgaps, and efficient thermoelectric performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Exploring spin-gapless featurs of IrCoNbX (X=Al, Ga, In) compounds via DFT. • Structural, electronic, magnetic, charge transfer and −COHP analysis are assembled. • Extant study demonstrated the stability of IrCoNbX compounds in magnetic phase. • Studied properties have been established via GGA and mBJ potentials for accuracy. • Electronic attributes unveiled their potential use in spin based applications. An investigation has been conducted on the spin-polarized structural, electronic, charge transfer, −COHP and magnetic behaviour of IrCoNbX (X=Al, Ga, In) alloys. To corroborate the studied properties the generalized gradient approximation (GGA), modified Becke Johnson (mBJ) and DFT+U schemes within the framework of density functional theory. The structures found comparatively more stable in spin-polarized phase than non-spin polarized phase. Based on electronic band structure and electronic density of states' analysis IrCoNbX alloys have demonstrated spin-gapless features in spin ↑ channel and semiconducting characteristics in spin ↓ channel. The −COHP examination revealed that Nb-Ir pair exhibited significantly stronger bonding interaction in comparison to X Co (X Al, Co, In, Nb) bonding pairs in IrCoNbX alloys. Each of the studied alloys manifested an integer value of the total magnetic moment of 2.0 μ B /f.u under mBJ scheme. The findings of current study proposed the experimental investigation of these alloys for potential applications in spintronics field. [ABSTRACT FROM AUTHOR]

We employ PF-LAPW (full-potential linear augmented plane-wave) integrated within DFT (density functional theory) for a comprehensive exploration of the structural, optoelectronic, and mechanical properties of novel Tungsten-based oxides double-perovskites compounds Sr 2 XWO 6 (X= Mn, Fe) through the quantum mechanical WIEN2K simulation package. All the computations are done by considering TB-mBJ (Tran-Blaha modified Becke-Johnson potential) and GGA (generalized gradient approximation) as the exchange-correlation potential. The stability and formation of the Sr 2 XWO 6 (X= Mn, Fe) compounds in a cubic structure are validated through structural optimization and the tolerance factor. The analysis of elastic constants and Born-Huang stability criteria predict that the interested oxide double perovskites are ductile, mechanically stable, hard to scratch, anisotropic, and possess a dominant covalent bonding. Both Sr 2 MnWO 6 and Sr 2 FeWO 6 materials are indirect semiconductors with a band gap of 2.05 eV for Sr 2 FeWO 6 and 1.98 eV for Sr 2 MnWO 6 from W-L symmetry points within the 1st Brillouin zone. The small values of band gap and various parameters of optical properties, specifically the broad monotonically increasing absorption spectra, reveal that novel Tungsten-based oxides double-perovskites compounds Sr 2 XWO 6 (X= Mn, Fe) exhibit great potential for optoelectronic properties. [ABSTRACT FROM AUTHOR]

Tetrahedrite (copper antimony sulfosalt) is a promising p -type thermoelectric material due to its very low intrinsic thermal conductivity and moderately-high power factor, with one of the limitations being the lack of n -type variant to create a thermoelectric generator. In this paper, DFT calculations have been carried out to study tetrahedrite doped with Li into structural voids, Li x Cu 12 Sb 4 S 13 (0 ≤ x ≤ 3). Enthalpies of formation show that the introduction of Li into both 6b and 24 g sites is energetically favorable. Dopants in those positions differently affect the rattling Cu(12e) behavior, as well as vary in the magnitude of induced local disorder. Topological analysis of charge density classifies tetrahedrite as a closed-shell, ionic system of interactions with some degree of covalency. The addition of Li increases bond strain and decreases structural stability. Electronic band structure shows that for x > 2. 0 , material becomes n -type; however, results are not precisely conclusive on whether structure will be synthesizable, which should be determined experimentally. [Display omitted] • Li-doped (into 24 g and 6b sites) tetrahedrite were investigated. • Enthalpy of formation and global instability index shows stability drop at x > 2. 0. • Dopants at 6b and 24 g site affect ratting Cu(12e) drastically different. • Band structure calculations predict tetrahedrite to be n -type for x > 2. 0. [ABSTRACT FROM AUTHOR]

The objective of this work is to use density functional theory (DFT) analysis to explain the effects of sulfur (S), selenium (Se), and oxygen vacancies on the mechanical, electrical, optical, dynamical, and thermoelectric properties of KTaO 3. Our investigation has uncovered important modifications to KTaO 3 many characteristics, most notably to its band gap values. Crucially, every chemical that was studied showed evidence of both dynamical and mechanical stability. These compounds are also good prospects for a variety of optoelectronic applications due to their promising optical properties, which include strong optical conductivity throughout the visible spectrum, low reflection, and high absorption coefficients. Our thorough analysis has shown the remarkable electrical, optical, and mechanical characteristics, including high absorptivity, low reflectivity, hardness, ductility, and semiconducting behavior. It has also highlighted the stability of all computed phases. The optical characteristics and adjusted band gap of KTaO 3 indicate that it has substantial potential for use in solar cells, providing avenues for improving the efficiency of solar energy conversion. In addition, the exceptional heat conductivity of KTaO 3 offers exciting opportunities for its use as a heat sink material. • First principle investigation on the effect of S/Se and oxygen doping on the properties of KTaO3. • Structural and elastic properties show that these elements present low formation energy and its mechanically stable. • These compounds show high absorption in the UV-Visible range of the spectrum which reveal applicability in photovoltaics. • The enhanced Seebeck coefficient and an improved power factor with temperature range 50-800 K is revealed from TE properties. [ABSTRACT FROM AUTHOR]

• Structural Stability: ZnLiCl 3 and ZnLiF 3 crystallize in the cubic Pm-3 m (No. 221) space group, confirmed to be stable via DFT calculations using the WIEN2k package. • Band Gap Analysis: ZnLiCl 3 has an indirect band gap of 0.30 eV (semiconducting), while ZnLiF 3 has an indirect band gap of 5.45 eV (insulating), based on electronic band structure calculations. • Electronic Structure: The total and partial density of states (TDOS and PDOS) were analyzed, identifying the electronic states contributing to the band structure for both compounds. • Optical Properties: Both materials exhibit strong optical conductivity and absorption in the higher energy range (0–14 eV) and transparency to lower-energy photons, making them highly suitable for UV applications. • Application Potential: The study suggests ZnLiCl 3 and ZnLiF 3 as promising candidates for high-frequency UV optoelectronic devices due to their optical and electronic characteristics. The zinc-based perovskites ZnLiX 3 (X = Cl or F) were investigated for their structural, electronic, and optical properties using the WIEN2k package within density functional theory (DFT). Structural properties were calculated using the generalized gradient approximation (GGA), while the modified Becke-Johnson (mBJ) potential was applied for a more accurate description of the optical and electronic properties. Both compounds are confirmed to be stable, crystallizing in the cubic Pm-3 m (No. 221) space group. ZnLiCl 3 has an indirect band gap of 0.30 eV between the Γ and M symmetry points, indicating semiconducting behaviour, while ZnLiF 3 exhibits an indirect band gap of 5.45 eV, typical of an insulating material. The electronic states contributing to the band structure were analyzed using the total density of states (TDOS) and partial density of states (PDOS). Optical properties, evaluated in the energy range of 0–14 eV, reveal strong optical conductivity and absorption at higher energies, while both materials show transparency to lower-energy photons. These findings suggest that ZnLiCl 3 and ZnLiF 3 are suitable candidates for high-frequency UV optoelectronic device applications. [ABSTRACT FROM AUTHOR]

Through first-principles investigation, two new Mn2-based full-Heusler alloys, Mn2HfSi and Mn2HfGe, have been studied using the full-potential linearized augmented plane wave (FP-LAPW) approach as implemented in the WIEN2k code. Our study focuses on these compound's stability (thermodynamic, dynamic, and mechanical), electronic, and magnetic properties. The L21 (Cu2MnAl-type) structure is shown to be more energetically favorable than the XA (Hg2CuTi-type) structure for both compounds, Mn2HfX (X = Si and Ge). We demonstrate that Mn2HfX (X = Si and Ge) are stable through the calculations of cohesive, formation energies, phonon dispersion curves, and the elastic constants, with the illustration of 3D and 2D bulk and Young's moduli. Using GGA and GGA-mBJ calculations show that Mn2HfX (X = Si and Ge) are half-metallic ferrimagnets (HMFs), with indirect band gap through the altered Becke-Johnson (mBJ), GGA approximation: 0.689 eV for Mn2HfSi and 0.520 eV for Mn2HfGe. Furthermore, the electrons at the Fermi level (EF) were fully spin-polarized. The total magnetic moment in these two compounds was found to have an integer value of 2 µB per formula, which complies with the Slater-Pauling rule Mtot = Ztot − 24. These compounds are favorable materials for spintronic applications. It was revealed that Mn2HfSi and Mn2HfGe maintained their half-metallicity for lattice constants in the range of 5.7–6.2 Å and 5.75–6.2 Å, respectively. [ABSTRACT FROM AUTHOR]

Prediction of new materials is crucial for the advancement of technology. Here, in this research work, the first-principle computation has been conducted utilizing the WIEN2K package to probe the structural, electronic, mechanical, and optical properties of barium-based chloroperovskites BaMCl3 (M = Ag, Cu) compounds. The optimized lattice constants are calculated for both compounds which are 9.90 Bohr for BaAgCl3 and 9.38 Bohr for BaCuCl3. To obtain better and more precise results for the electronic band's structure, TDOS and PDOS (total and partial density of states), and the TB-mBJ potential approximation are employed. The indirect band gap (R–Γ) is found for both compounds having values of 1.173 eV and 2.30 eV for BaCuCl3 and BaAgCl3, respectively, which depicts its semiconducting nature. The calculation of elastic properties is conducted with IRelast code. The Cauchy pressure, Bulk modulus, Young's modulus, Shear modulus, anisotropic ratio, Kleinman parameters, and Poisson's ratio are calculated from the obtained elastic constants. The computation of elastic parameters indicates that the interested chloroperovskites are anisotropic, mechanically stable, hard to scratch, and ductile. From 0 eV to 40 eV incident photon energy ranges, the various optical parameter such as refractive index, absorption coefficient, dielectric function, reflectivity, extinction coefficient, and optical conductivity are analyzed. These compounds absorb maximum light within 5 to 25 eV incident photon energy. Hence, these materials are good light absorbers, therefore, they can be used in optoelectronic devices for high-frequency applications. [ABSTRACT FROM AUTHOR]

The structural, electronic, optical, and thermoelectric properties of Cs-based CsXAs (X = Ca, Sr, Ba) cubic compounds have been studied through density functional theory. The electronic properties are described through band structure and density of states which show that the studied materials have direct bandgap located at gamma symmetric point. The optical behavior of these materials has been analyzed in terms of absorption coefficient, dielectric function, refractive index, reflectivity, optical conductivity, energy loss, and extinction coefficient. Moreover, the BoltzTraP code is used to study the material response to temperature, and it has been elaborate through electrical conductivity, thermal conductivity, power factor, and Seebeck coefficient. Thermoelectric and optical properties of these materials are studied through first principle calculation, and it develops a new route towards the potential energy renewable devices. [ABSTRACT FROM AUTHOR]

Safer and more environmentally friendly alternatives to lead-based perovskites include lead-free halide perovskites, which retain good optoelectronic capabilities while reducing environmental toxicity. They also align better with ecological and regulatory standards for green technologies. In this manuscript, we have presented the first principles analysis of the physical traits of A 2 InGaBr 6 (A=K, Rb, Cs). The exchange-correlation effects are treated with mBJ potential. The structural characteristic of A 2 InGaBr 6 (A=K, Rb, Cs) was assessed through the volume optimization curves, formation energies and tolerance factor. The elastic properties of the studied halides are analyzed through elastic constants. The electronic band structures revealed indirect bandgaps for K 2 InGaBr 6 , Rb 2 InGaBr 6, and Cs 2 InGaBr 6 . The optical properties indicate promising potential in the fabrication of optoelectronic devices for A 2 InGaBr 6 (A=K, Rb, Cs). The transport properties for the studied halides are computed using the BoltzTraP code, which reveals that these halides are promising candidates for thermoelectricity., (© 2024 Wiley-VCH GmbH.)