In this study, we used the FP-LAPW technique based on density functional theory applied in WIEN2k code to examine the structural, electronic, elastic, and thermoelectric properties of cubic double perovskite Rb₂InBiX₆ (X = Cl, Br) compounds. The structural stability was confirmed from the tolerance factor, formation energy, and phonon dispersion. The exchange-correlation potentials LDA, GGA, mBJ, and HSE were used to estimate the electronic properties. According to the band structure computed band gap using mBJ, the HSE are 1.61 eV, 1.81 eV for Rb₂InBiCl₆ and 1.22 eV, 1.32 eV for Rb₂InBiBr₆ compounds, respectively. The mechanical stability of the materials under examination were reflected by the calculated elastic constants. The estimated bulk modulus-to-shear modulus ratios for Rb₂InBiX₆ (X = Cl, Br) are 2.13 and 3.65, respectively. This indicates that the examined compounds were ductile in nature. The optical properties in terms of real and imaginary dielectric functions, refractive index, and absorption coefficient were computed, indicating that they might be employed in optoelectronic and photovoltaic applications. In the temperature range 200–800 K, the electrical conductivity, Seebeck coefficient, thermal conductivity, and power factor (PF) were analysed. Relatively high PFs of about 2.7 × 10¹⁰ W/K² ms and 3.1 × 10¹⁰ W/K² ms were obtained for Rb₂InBiX₆ (X = Cl, Br) suggesting that these compounds are viable for usage in thermoelectric devices. Both the compounds showed strong absorption patterns and excellent PF signifying that these are suitable materials for photovoltaic and thermoelectric applications.

In this work, the structural, elastic, electronic, thermodynamic, optical, and thermoelectric properties of cubic phase SnTiO₃ employing first-principles calculation are examined. The calculations of all parameters via various potentials such as LDA, PBE-GGA, WC-GGA, PBEsol-GGA, mBJ-GGA, nmBJ-GGA, and HSE are performed. The computed band structure yields an indirect bandgap of 1.88 eV with the HSE approach. The optical parameters have been evaluated through absorption, dispersion, and loss function. For cubic phase SnTiO₃, the maximum absorption coefficient $\alpha \left(\omega \right)$ is 173 × 10⁴ (cm)⁻¹ at high energy region 9 eV. The thermoelectric properties of the SnTiO₃ have been explored by the Seebeck coefficient, thermal conductivity, and power factor employing the BoltzTrap code with temperature and chemical potential. Furthermore, the thermodynamic quantities under high pressure (0–120 GPa) and temperature (0–1200 K) are also calculated.

Modern manufacturing is aiming for products that are readily available, environmentally sustainable, and energy efficient. This paper delves into the exploration of compounds meeting these criteria. Specifically, we investigate the structural, elastic, optoelectronic, and transport properties of XSnBr₃ (X = Rb/Cs) compounds utilizing the full-potential linearized augmented plane wave program (FP LAPW), a component of Wien2K software. Structural optimization is carried out through the generalized gradient approximation (GGA) approach, yielding lattice constants consistent with preceding numerical and experimental studies. The explored XSnBr₃ (X = Rb/Cs) materials exhibit ductility and mechanical stability. Notably, XSnBr₃ (X = Rb/Cs) displays a direct bandgap, signifying its semiconducting nature. The bandgap values, as determined by the modified Becke–Johnson (mBJ) approach, stand at 2.07 eV for X = Rb and 2.14 eV for XSnBr₃ (X = Rb/Cs). Furthermore, utilizing the BoltzTraP software’s transport feature, we investigate thermoelectric properties. Remarkably, XSnBr₃ (X = Rb/Cs) demonstrates impressive figures of merit (ZT) at room temperature, implying its potential to serve as a material for highly efficient thermoelectric devices. This research holds promise for contributing to the development of environmentally friendly and energy-efficient technologies.

This work focuses on study of the structural, electronic, thermodynamic and thermoelectric properties of RbNbCd and RbNbZn Half Heusler (HH), utilizing a full-potential linearized augmented plane wave (FP-LAPW) approach and the Boltzmann transport equation using a constant relaxation time approximation within the context of density functional theory (DFT) as embedded in the WIEN2k code. The structural analysis employed the generalized gradient approximation (GGA) and considered the Birch Murnaghan equation of state (EOS), which results in the stable phase for RbNbCd and RbNbZn. The positive phonon spectra indicate the dynamical stability of the studied RbNbCd and RbNbZn. The compounds under investigation that have no bandgap are metallic, as evidenced by their electronic properties. Their mechanical and thermal stability as well as their anisotropic and ductile character are confirmed by the various elastic and thermodynamic parameters. The lattice thermal conductivity has been calculated. This thorough analysis demonstrates the applicability of the studied RbNbCd and RbNbZn for thermoelectric applications.