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.

This article presents a theoretical investigation into the effects of lanthanum doping on the optoelectronic properties of TiPbO3, conducted through first-principles calculations. TiPbO3, a widely used ferroelectric material, is pivotal in various optoelectronic applications due to its high dielectric constant and good optical properties. However, enhancing its properties for tailored applications is necessary to keep pace with the advancing technological frontiers. We analyze the impact of La-doping on the bandgap, absorption coefficient, density of states, and dielectric function, using comprehensive computational simulations. The results indicate significant modifications in the electronic structure and optical behavior of TiPbO3 upon doping, which could result in improved performance in optoelectronic devices. The methodology employed includes density functional theory calculations with CASTEP, utilizing an energy cutoff of 500 eV. The obtained results suggest that La-doped TiPbO3 can be optimized for a variety of optoelectronic applications, offering a pathway towards the development of advanced functional materials.

BaTiO3 is a model perovskite oxide that holds promise for high efficiency photovoltaic devices and next-generation 3D printing because it can have tunable optoelectronic and mechanical properties. In this work, we utilized density functional theory calculations with the CASTEP code and explored BaTiO3 under hydrostatic pressure. Our simulations illustrate that pressure is accompanied by a strong tendency for significant structural contractions that are characterized by lattice parameter shrinkage, and bond lengths reductions. The electronic band gap is highly dependent upon pressure; 1.71 eV (indirect, M–G) at 0 GPa, followed by 1.94 eV at 100 GPa, then reduced to 1.64 eV at 200 GPa, and consistently lowered to 1.34 eV at 300 GPa and then narrowed to around 0.91 eV at 400–500GPa. These band gap alterations pushed the optical absorption edge to wavelengths which are more favorable for photovoltaic applications. Device simulations using SCAPS-1D of photovoltaic devices under pressure, also demonstrated improved performance under pressure. At 0 GPa, the device has a power conversion efficiency (PCE) of 15.23% with an open-circuit voltage (Voc) of 0.7664 V, a short-circuit current density (Jsc) of 24.73 mA/cm², and a fill factor (FF) of 80.34%. As pressure is applied, these parameters significantly increased: at 300 GPa, Voc improved to 0.7729 V, Jsc increased to 30.40 mA/cm², FF is 79.39%, PCE improved to 18.65%; at 400 GPa, Voc improved to 0.7840 V, Jsc was 45.61 mA/cm², FF was 84.53%, and PCE improved to 30.23%, and similar values were observed at 500 GPa. With the elastic constants determined, it can be seen that the measured stiffness increased, and the favorable trend toward higher ductility increased as pressure was applied and is in support of incorporating BaTiO3 into mechanically resilient 3D-printed parts. All of this points to pressure engineering as a viable method for optimizing BaTiO3 for multifunctional optoelectronic and advanced manufacturing applications.