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Lead‐free double perovskites are unique materials for transport and optoelectronic applications that use clean resources to generate energy. Using first‐principle computations, this study thoroughly investigates the structural, thermoelectric, and optical attributes of A2TlAgF6 (A = Rb, Cs). Tolerance factor and formation energy estimates are used to verify that these materials exist in the cubic phase. Elastic constants with high melting temperature values are ductile when evaluated for mechanical stability using the Born stability criterion. The optical absorption band is adjusted from 2 to 4 eV via band gaps of 1.88 and 1.99 eV, as indicated by band structures. Analysis of optical properties reveals perfect absorption in the visible spectrum, whole polarization, and low optical loss. Furthermore, thermoelectric properties are assessed at 300, 500, and 700 K in the range of −0.5 to 3 eV for chemical potential (μ). The materials exhibit significant improvements in the Figure of Merit scale due to their elevated electrical conductivity, Seebeck coefficient, and extremely low thermal conductivity values. [ABSTRACT FROM AUTHOR]

This article introduces and examines a new type of lead-free double perovskites, K2InSbX6 (X = Cl, Br) for their potential use in optoelectronic and thermoelectric devices. The investigation is conducted through theoretical exploration. The physical features of the materials were investigated using density functional theory. Both compounds are found stable in their cubic structure. Elastic constants and negative formation energies computed for K2InSbX6 demonstrate its mechanical and thermodynamic stability. According to the computed Poisson, Pugh's ratio, and anisotropy, both materials are brittle and show anisotropic behavior. Furthermore, the calculated findings show that K2InSbCl6 and K2InSbBr6 have direct bandgap values of 1.31 and 1.22 eV, respectively. Optical analysis reveals a notable ability to absorb visible and near-UV radiation. Perovskite K2InSbX6's excellent light absorption capabilities and narrow band gap make it a great choice for utilization in solar cell applications and other optoelectronic devices. Furthermore, the findings of transport characteristics indicate that the materials possess exceptional electrical and thermal conductivity and are projected to exhibit optimal thermoelectric capabilities at a temperature of 300 K. [ABSTRACT FROM AUTHOR]

Recently, many studies have been done on MXene (2D titanium carbide) for energy storage applications. It possesses outstanding features like hydrophobicity, conductivity, and particularly strong surface redox reactivity, which are essential for energy storage applications. Despite these exceptional properties, MXene's electrochemical performance is significantly impacted by certain deficiencies, such as the inability to assemble MXene sheets. To prevent MXene sheets from restacking, the spaces between them must be filled with an appropriate material. Metal-organic frameworks (MOFs) for electrochemical applications have also been extensively studied. Due to their high crystallinity, porous structure, and substantial surface area, MOFs find diverse applications, but their efficacy as electrode materials is hindered by a lower specific capacity and charging/discharging rate. Addressing these limitations, combining MOFs with suitable materials is preferred for enhanced performance. This study suggests an innovative approach: a composite between Cu-BTC MOF and N-MXene. By shortening both the ion/electron diffusion pathways and improving the electroactive sites, the prevention of MXene sheet restacking was achieved, leading to exceptional specific and rate capacity in the composite with MOFs. The Cu-BTC/N-MXene-decorated electrode exhibited energy and power density reaching approximately 65.23 W h kg-1 and 923 W kg-1 in a two-electrode (real device) configuration. Cu-BTC/N-MXene//N-MXene retained 99% of its capacity and a coulombic efficiency of 92% after 8000 alternate GCD cycles. The findings of this investigation highlight the significant potential of employing the innovative electrode material Cu-BTC/N-MXene for supercapattery applications. [ABSTRACT FROM AUTHOR]

In this work, theoretical investigations were performed for the structural, elastic, optoelectronic, thermodynamic, and thermoelectric characteristics of barium ceroplatinate Ba2CePtO6 double perovskite oxide. The direct band gaps 1.518 eV and 1.385 are calculated with TB-mBJ potential, and PBE-GGA approximation. The findings of elastic constants C11, C12 and C44, ensure the mechanical stability, ductile nature, anisotropic, Debye temperature, and ionic bonding. In visible and ultraviolet spectrums, Ba2CePtO6 exhibits a high absorption coefficient (> 105 cm−1), low optical reflectivity, low electron energy loss and excellent refractive index. Finally, the thermoelectric properties are computed using BoltzTraP code. At room temperature the figure of merit has been reported as 0.84 and 0.998. Therefore, the reported results are likely to serve as an inspiration for the forthcoming experimental and theoretical investigations. [ABSTRACT FROM AUTHOR]

We investigated the magnetic and thermoelectric properties of REMoN3 (RE = La, Ce, Pr, Nd, Sm) perovskites using the full potential linearized augmented plane wave (FP‐LAPW) method. To overcome the problem of underestimation of electronic interaction, we employed the DFT + U approach to accurately map the electronic structure of these compounds. Our study shows an increasing trend in the magnetic moments with the increasing number of unpaired electrons in RE. Among these compounds, SmMoN3 possesses a large magnetic moment, which is suitable for applications such as memory devices and sensors. Interestingly, all these perovskites display ferromagnetic behavior except CeMoN3, which exhibits an antiferromagnetic nature. Furthermore, our analysis indicates n‐type thermoelectric behavior in all these materials. The compound, namely PrMoN3, exhibits a high figure of merit among REMoN3, which can be improved by modifying the lattice sites. [ABSTRACT FROM AUTHOR]

This article comprehensively explores the structure, stability, mechanical, optoelectronic, and thermoelectric aspects of the emerging double perovskites A2YCuZ6 (A = Rb, Cs and Z = Cl, Br). The structural and mechanical characteristics are estimated using the PBE-GGA functional, whereas the optoelectronic and thermoelectric characteristics are computed using the modified Becke and Johnson potential. Tolerance factor, formation energies, and Gibbs free energies have validated the cubic phase and thermodynamic stability. The anticipated elastic values indicated that all the materials exhibited mechanical stability, ductility, and anisotropic behavior. The computed electronic features verified that Rb2YCuCl6, Rb2YCuBr6, Cs2YCuCl6, and Cs2YCuBr6 have indirect band gaps of 1.95, 1.30, 1.55, and 1.2 eV, respectively. This work also explores the optical response in the energy range 0 to 6 eV in terms of polarization, refractive index, absorption, and optical conduction. The visible and ultraviolet ranges of light are both significantly absorbed, making these materials optimal for use in solar systems. The BoltzTraP code has been used to calculate the transport parameters, demonstrating the p-type semiconductors nature of these materials. Further, the significant merit values of 0.77, 0.83, 0.82, and 0.81 at room temperature for analyzed materials suggest their potential applicability in thermoelectric devices. Hence, the investigated double perovskites, which are not empirically validated, have been recommended as extremely suitable alternatives for creating various energy conversion applications. [ABSTRACT FROM AUTHOR]

Lead-free halide double perovskites (HDPs) have emerged as aspirant members of the optoelectronic and thermoelectric (TE) materials family due to their non-toxicity, tunable and noticeable performances. Herein, the structural, mechanical, thermodynamic, optoelectronic, and TE properties of novel Rb2CuMF6 (M = As3+, Bi3+) HDPs are comprehensively investigated. This study has been performed using accurate first principle calculations with the Boltzmann transport theory. The evaluated elastic constants ensure their structural and thermal stability in cubic phase and anisotropic with ductile behavior. Using Tran-Balaha modified Becke-Johnson (TB-mBJ-GGA) potential, indirect semiconducting band gaps of 1.43 eV and 1.27 eV are recorded for Rb2CuAsF6, and Rb2CuBiF6, respectively. Correlated analyses of the wavelength-dependent optical properties are conducted. The studied HDPs exhibited different optical absorption abilities in both UV and VIS working regions. Besides, the entire TE properties are addressed for n- and p-type doping in a wide operating temperature range. The p-type doping is found to be effective in enhancing the TE performances of both HDPs. The highest figure of merit (ZT)max = 0.994 is recorded at 300 K for intrinsic Rb2CuMF6 (M = As3+, Bi3+). Accordingly, the favorable combination of the present outcomes makes Rb2CuMF6 (M = As3+, Bi3+) an interesting candidate for widespread optoelectronic and TE applications in a wide working temperature range. [ABSTRACT FROM AUTHOR]

Lead-free double perovskites are unique materials for transport and optoelectronic applications that use clean resources to generate energy. Using first-principle computations, this study thoroughly investigates the structural, thermoelectric, and optical attributes of A 2 TlAgF 6 (A = Rb, Cs). Tolerance factor and formation energy estimates are used to verify that these materials exist in the cubic phase. Elastic constants with high melting temperature values are ductile when evaluated for mechanical stability using the Born stability criterion. The optical absorption band is adjusted from 2 to 4 eV via band gaps of 1.88 and 1.99 eV, as indicated by band structures. Analysis of optical properties reveals perfect absorption in the visible spectrum, whole polarization, and low optical loss. Furthermore, thermoelectric properties are assessed at 300, 500, and 700 K in the range of -0.5 to 3 eV for chemical potential (μ). The materials exhibit significant improvements in the Figure of Merit scale due to their elevated electrical conductivity, Seebeck coefficient, and extremely low thermal conductivity values., (© 2024 Wiley Periodicals LLC.)