Computational Exploration of Structural, Electronic, and Optical Properties of Novel Combinations of Inorganic Ruddlesden-Popper Layered Perovskites Bi2XO4 (X = Be, Mg) using Tran and Blaha-Modified Becke-Johnson Approach for Optoelectronic Applications

Herein, the layered perovskites Bi2XO4 (X = Be, Mg) have been taken into account to probe into their structural and optoelectronic behavior using an ab initio technique which is solely reliant on density functional theory (DFT). To compute an improved electronic bandgap and encounter accurate contribution from d/f electronic states, the Tran and Blaha-modified Becke-Johnson functional is used systematically, which has been considered an adequate approach to overcome limitations of the PBE-GGA functional. The conduction band minima (CBM) and the valence band maxima (VBM) are located at different values of the wave vectors yielding a noticeable indirect energy gap such as 2.80 eV for Bi2BeO4 and 2.40 eV for Bi2MgO4, which discloses that studied perovskites belong to the semiconductor category. The density of states exposes that Bi-6p states contribute in the conduction region in vicinity of 5 eV energy. Whereas Be-s orbitals are contributing in the far region of the conduction bands. O-2p states are located in lower energy range associated with valence bands. Large values of formation and cohesive energy of compounds indicate that these are more stable and not easily decomposable under ambient conditions. The minimal reflectivity endorses our contention that these perovskites might be very useful for potential applications in optoelectronics.