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The current study utilized DFT (density functional theory) calculations to examine the influence of Ca-doping on the optoelectronic properties of Ra0.875Ca0.125TiO3 (RCT12), Ra0.75Ca0.25TiO3 (RCT25), and Ra0.625Ca0.375TiO3 (RCT37). We utilize the FP-LAPW + lo (full potential linearized augmented plane wave plus local orbital) method in order to solve the Kohn–Sham equations using the generalized gradient approximation (GGA). The GGA model along with Hubbard potential (GGA + U) is utilized to compute fundamental properties of the studied perovskites. The energy bandgap values for RCT12, RCT25, and RCT37 are around 1.96, 1.92 and 1.87 eV, respectively. From the obtained ε 2 (ω) spectra, it is evident that RCT12, RCT25, and RCT37 compounds shows a substantial absorption of incoming photons in the visible and near UV region. The computed values of n (ω) for RCT12, RCT25, and RCT37 are 1.79, 1.77 and 1.76, respectively. The aforesaid compounds having n (ω) values in the range of 1.0 and 2.0 are regarded as active optical materials. The optoelectronic characteristics of RCT12, RCT25, and RCT37 suggest that they have promising potential for use in energy-related applications like solar cells. [ABSTRACT FROM AUTHOR]

One of the primary objectives of scientific research is to create state-of-the-art multiferroic (MF) materials that exhibit interconnected properties, such as piezoelectricity, magnetoelectricity, and magnetostriction, and remain functional under normal ambient temperature conditions. In this study, we employed first-principles calculations to investigate how changing pnictogen elements affect the structural, electronic, magnetic, and optical characteristics of QFeO3 (Q = Bi, P, SB). Electronic band structures reveal that BiFeO3 is a semiconductor compound; however, PFeO3 and SbFeO3 are metallic. The studied compounds are promising for spintronics, as they exhibit excellent magnetic properties. The calculated magnetic moments decreased as we replaced Bi with SB and P in BiFeO3. A red shift in the values of ε 2 (ω) was evident from the presented spectra as we substituted Bi with Sb and P in BiFeO3. QFeO3 (Q = Bi, P, SB) showed the maximum absorption of incident photons in the visible region. The results obtained from calculating the optical parameters suggest that these materials have a strong potential to be used in photovoltaic applications. [ABSTRACT FROM AUTHOR]

• Optoelectronic and thermodynamic, properties of ATiO 3 (A = Ba, Ca, Ra) are investigated using first-principles method. • ATiO 3 (A = Ba, Ca, Ra) shows efficient photon absorption in near UV regions. • ATiO 3 (A = Ba, Ca, Ra) show high thermodynamic stability and is a promising candidate for device applications. • These compounds are optically active compounds as their refractive index occurs between 1.0 and 2.0. The structural, optoelectronic, and thermodynamic characteristics of ATiO 3 (A = Ba, Ca, Ra) perovskites have comprehensively been investigation first-principles based DFT calculations. The GGA method was employed to handle exchange and correlation potentials. The analysis of the E-V plots indicates that RaTiO 3 exhibits the highest level of stability in comparison to BaTiO 3 and CaTiO 3. The direct band-gap characteristic of the ATiO 3 (A = Ba, Ca, Ra) perovskites is apparent in the band structure plots. The band gaps for BaTiO 3 , CaTiO 3 , and RaTiO 3 are 2.48, 3.15, and 1.91 eV, respectively. The analyzed materials exhibit the highest level of photon absorption in the near UV area, as demonstrated in the ε 2 (ω) plots. The refractive index n (ω) values reveal that ATiO 3 (A = Ba, Ca, Ra) are active optical materials as their n (ω) values are between 1 and 2. These perovskite oxides have optical features that make them promising prospects for anti-reflecting coatings over entire energy span as these materials exhibits a very low reflection (∼20 %) of incident photons. The thermodynamic properties of ATiO 3 (A = Ba, Ca, Ra) are assessed to determine their dynamical stability and suitability for thermal applications. The results of the investigation demonstrate that these perovskite oxides have the potential to be used in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Hydrogen is a promising clean energy source to address the energy issue as well as the environmental and health risks of current energy sources. Metal hydrides have demonstrated significant potential for storing hydrogen. The perovskite hydrides AMgH 3 (A = Be, Ca) have demonstrated potential for hydrogen storage applications due to their impressive gravimetric hydrogen density of 8.32 and 4.49 wt% for BeMgH 3 and CaMgH 3 , respectively. The calculated results indicate that AMgH 3 (A = Be, Ca) perovskite hydrides exhibit metallic character. The AMgH 3 (A = Be, Ca) compounds mostly absorb quanta of energy in the IR range, but they also exhibit high absorption in the UV region. The formation enthalpies of these hydrides have been found to be negative, indicating that they are thermodynamically stable. Furthermore, it has been established that these perovskite hydrides are mechanically stable as they fulfil Born stability criteria. [Display omitted] • Hydrogen storage properties of AMgH 3 (A = Be, Ca) are investigated using DFT approach. • AMgH 3 (A = Be, Ca) show metallic character as their energy bandgap value is 0 eV. • They show remarkable gravimetric H-densities of 8.32 and 4.49 wt%. • AMgH 3 (A = Be, Ca) perovskite hydrides exhibit thermodynamic and mechanical stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structural, optoelectronic, and thermophysical properties of Nb-based pyrochlore oxides A 2 Nb 2 O 7 (A = Ba, Mg and Sr) are investigated using ab-initio calculations. • A 2 Nb 2 O 7 (A = Ba, Mg and Sr) are narrow band semiconductors. • The ZT values for Mg2Nb2O7 [0.998] and Sr2Nb2O7 [0.996] make them favorite candidates for TE device applications. • Optical spectra show major absorption peaks for these pyrochlore oxides occur in near UV region. The present study employed first-principles DFT (density functional theory) computations to investigate the impact of alkaline metal substitutions on the structural, optoelectronic, thermodynamic, and thermoelectric characteristics of Nb-based pyrochlore oxides A 2 Nb 2 O 7 (A = Ba, Mg and Sr). The PBE-GGA model is employed to calculate the fundamental characteristics of Nb-based pyrochlore oxides. An in-depth analysis of the energy band structures reveals that these Nb-based pyrochlore oxides are semiconductor compounds of A 2 Nb 2 O 7 (A = Ba, Mg, and Sr) reveals that these Nb-based pyrochlore oxides are semiconductors. The energy bandgap values are around 0.6, 3.05, and 1.4 eV for Ba 2 Nb 2 O 7 , Mg 2 Nb 2 O 7 , and Sr 2 Nb 2 O 7 , respectively. Based on the observed ε 2 (ω) spectra, it is apparent that the A 2 Nb 2 O 7 (A = Ba, Mg, and Sr) compound, exhibits a significant absorption of incident photons in the near UV region (at approximately 5.0 eV). The calculated values of n (ω) are 1.71, 1.66 and 1.63 for Ba 2 Nb 2 O 7 , Mg 2 Nb 2 O 7 and Sr 2 Nb 2 O 7 , respectively. The values of ZT are 0.661, 0.998 and 0.996 for Ba 2 Nb 2 O 7 , Mg 2 Nb 2 O 7 and Sr 2 Nb 2 O 7 , respectively, which make them favourite for TE device applications. The optoelectronic and thermoelectric properties of Nb-based pyrochlore oxides A 2 Nb 2 O 7 (A = Ba, Mg, and Sr) indicate their potential as favorable contenders for energy-related applications. The elucidated thermodynamic properties reveal that the Nb-based pyrochlore oxides A 2 Nb 2 O 7 (A = Ba, Mg, and Sr) display a high degree of thermal stability. [ABSTRACT FROM AUTHOR]

The first-principles based DFT calculations were used to investigate the effect of transition metal (TM) doping on structural, electronic, optical and thermoelectric properties of Sn 1-x A x Se (A = Au and Ag). The PBE-GGA approximation is used to calculate ground state properties of TM doped SnSe. These compounds show the presence of type-II intermediate band (IB) at Fermi level. A considerable energy bandgap is present between IB and conduction band. Significant contributions from Ag/Au and Se-atom in valence bands of Sn 1-x A x Se (A = Au and Ag) are evident from presented DOS spectra. The calculated Fermi surfaces and Seebeck coefficient (S) confirms p-type nature of these semiconductors. From ε 2 (ω) spectra, it is evident that Sn 1-x A x Se (A = Au and Ag) absorbs maximum number of incident photons in infrared (at ∼0.5 eV) and visible (at ∼2.2 eV) regions. The calculated values of n (ω) are 2.27 and 2.58 for Sn 1-x Ag x Se and Sn 1-x Au x Se, respectively. We can confirm that Sn 1-x A x Se (A = Au and Ag) are promising candidates for energy applications (especially solar cells) based on their optoelectronic and thermoelectric properties. [Display omitted] • Electronic, optical and thermoelectric properties of Sn 1-x A x Se (A = Ag and Au) are investigated ab-initio. • Sn 1-x A x Se (A = Ag and Au) show type-II intermediate band in their band structures. • These compounds are p-type materials based on Fermi surface and Seebeck coefficient. • Optical spectra show major absorption peaks in visible region around 2.2 eV. • Among the considered compounds, Sn 1-x Au x Se shows the highest absorption. [ABSTRACT FROM AUTHOR]