In this groundbreaking study, we unveil the remarkable structural, electronic, and optical Properties of the newly discovered double perovskite material, K₂AgBiI₆, presenting a paradigm shift in materials science. The unique crystal structure and diverse atomic interactions inherent in this double perovskite make it an up-and-coming candidate for various technological applications, particularly in photovoltaics; owing to its stability and resistance to heat and humidity, we aim to shed light on the extraordinary potential of K₂AgBiI₆. Our study provides valuable insights for researchers engaged in tailored material design. We anticipate that the exceptional electronic properties of K₂AgBiI₆will not only redefine the boundaries of materials engineering but also catalyze unprecedented advances in sustainable technology. Employing the powerful computational tool CASTEP, we conducted detailed electronic structure calculations within the framework of Density Functional Theory (DFT) to unravel the electronic properties of the double perovskite K₂AgBiI₆. Our investigation thoroughly explored structural properties, band structure, total density of states (DOS), and partial density of states (PDOS). Furthermore, we systematically examined the influence of different exchange-correlation functionals, including LDA, GGA, and m-GGA, on the electronic and optical features of the material by presenting a comparative analysis of these approximations.

In recent years, double perovskite oxides have gained attention as promising candidates in the realms of solar cells and catalysis. By adjusting their composition and engineering the band gap, numerous materials are being developed for energy-related applications. Oxide perovskites offer the benefit of a longer carrier lifetime compared to halide perovskites, which is advantageous for energy applications. In this study, we present a systematic theoretical analysis of a double perovskite oxide, examining his composition. The associated electronic and optical properties are discussed, along with prospects for identifying highly efficient materials within this family. This paper reports the study of electronic and optical properties of double perovskite oxide LaFeWO₆ by utilizing the FP − LAPW method within the framework of (DFT). Results of density of states and energy bands are presented. The direct band gaps have been found for the systems by using the GGA approximation. Calculations of optical properties is also presented by considering the variations of optical parameters as a function of incident photon energy. The results indicate that LaFeWO₆ exhibits a suitable band gap (0.71eV) for visible light absorption, along with promising electronic properties, making it a candidate for photocatalytic and photovoltaic applications.

The effects of cation substitution are the main emphasis of this investigation into the structural, mechanical, electronic, and optical properties of double perovskites K₂AgSbBr₆ and K₂NaScBr₆. Outwardly favorable tolerance and octahedral factors and negative formation energy confirmed structural stability and thermodynamic feasibility. Mechanical analysis showed that K₂AgSbBr₆ possesses greater volumetric stability and rigidity, while K₂NaScBr₆ exhibits greater ductility and isotropic characteristics. The electronic properties determined based on density functional theory (DFT) calculations indicate that K₂AgSbBr₆ has an indirect bandgap of 0.857 eV, making it suitable for applications using visible light, and K₂NaScBr₆ has a direct bandgap of 3.107 eV, making it ideal for UV-specific technologies. Optical analyses demonstrate complementary characteristics, particularly in terms of the dielectric function, absorption, reflectivity, energy loss function, refractive index, extinction coefficient, and optical conductivity. K₂AgSbBr₆ exhibits strong visible light absorptivity.

This study investigates the electronic and optical properties of calcium-doped strontium hydride (SrH₂) using first-principles density functional theory (DFT) calculations via the CASTEP code with generalized gradient approximation (GGA). We explore the impact of calcium (Ca) doping on the electronic band structure, density of states (DOS), and optical absorption spectra of SrH₂. Our results show that Ca doping significantly alters the electronic properties of SrH₂, notably increasing the indirect bandgap from 1.3 eV to 1.6 eV. The DOS analysis reveals new states near the Fermi level, primarily from Ca 3d orbitals. Moreover, the optical absorption spectra display enhanced absorption in the visible range, suggesting the potential for optoelectronic applications. This research highlights the feasibility of tuning the electronic and optical characteristics of SrH₂ through Ca doping, thus opening the way for the generation of advanced materials with tailored properties.