A first-principles calculation based on DFT investigations on the structural, optoelectronic, and thermoelectric characteristics of the newly designed pyrochlore oxides La₂Tm₂O₇ (Tm = Hf, Zr) is presented in this study. The main quest of the researchers working in the field of renewable energy is to manufacture suitable materials for commercial applications such as thermoelectric and optoelectronic devices. From the calculated structural properties, it is evident that La₂Hf₂O₇ is more stable compared to La₂Zr₂O₇. La₂Hf₂O₇ and La₂Zr₂O₇ are direct bandgap materials having energy bandgaps of 4.45 and 4.40 eV, respectively. No evidence regarding magnetic moment is obtained from the spectra of TDOS, as a similar overall profile for both spin channels can be noted. In the spectra of ${\epsilon }_2\left(\omega \right)$, it is evident that these materials absorb maximum photons in the UV region and are potential candidates for photovoltaic device applications. La₂Tm₂O₇ (Tm = Hf, Zr) are also promising candidates for thermoelectric device applications, as these p-type materials possess $ZT$ values of approximately 1, which is the primary criterion for efficient thermoelectric materials.

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 ${\epsilon }_2\left(\omega \right)$ 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.