In this research article, we present a density functional theory (DFT) oriented analysis to examine the optoelectronic and thermoelectric properties, along with the mechanical stability, of two proposed oxide perovskites, SbAlO3 and SbGaO3, based on the full potential linear augmented plane wave (FP-LAPW). The evaluated formation energy \({E}_{F}\) and tolerance factor (τF) show that considered perovskite-oxides were thermodynamically optimum with cubic cell. Generalized gradient approximation (PBE-GGA) along modified Beck Johnson potential (TB-mBJ) potential confirms direct bandgaps ( \({E}_{g}\) ) of 2.074 and 2.059 eV for SbXO3 (X = Al, Ga), respectively. The optical characteristics were investigated in the energy range of 0–10 eV. Optimal energy loss suggesting plasma resonance is at 9 eV and above 10 eV, maximum reflectivity at 52.12% and 56.96% at 6.25 eV and 7.50 eV for SbGaO3 and SbAlO3 respectively. Furthermore, thermoelectric features are determined using semiclassical Boltzmann theory with constant relaxation time approximation. Calculated figure of merit (zT) values for SbXO3 (X = Al, Ga) are 0.40 and 0.68 at 1200 K, respectively. Thermal parameters are crucial in establishing a material's thermal endurance over a broad spectrum of temperatures. We anticipate that the estimated characteristics of SbAlO3 and SbGaO3 compounds will pave the way for novel applications in optoelectronics and thermoelectric devices.
