Analyzing the physical properties of perovskite oxides CeBO₃ (B=Be, Mg) for optoelectronic and thermoelectric applications

Abstract

The structural, electronic, elastic, thermoelectric and optical properties of CeBO3 (B = Be, Mg) oxide perovskites were investigated using density functional theory. Exchange and correlation effects were addressed through the GGA approximation and the TB-mBJ potential. Thermodynamic stability was confirmed by assessing cohesive energy and formation enthalpy. The band structures reveal a semiconductor nature with a moderate indirect band gap of 0.73 (CeBeO3) and 0.51 (CeMgO3). The TB-mBJ approximation has enhanced the gap value with a 55% approaching rate. These compounds exhibited a rigid and elastically anisotropic behavior with chemical bonds manifesting as a mixture of metallic and covalent types. The CeBeO3 displayed ductility while CeMgO3 exhibited brittleness. The optical examination suggests that these oxides exhibit activity across a broad range of the electromagnetic spectrum. Their strong reflectivity in the near-infrared region was particularly noteworthy suggesting potential use as effective shields in this domain. The replacement of beryllium with a magnesium atom enhanced thermoelectric performance by reducing thermal conductivity and increasing the merit factor. Based on the obtained results, the semiconductor perovskites CeBeO3 and CeMgO3 hold promise for efficient applications in optical and thermoelectric devices.