First-principles calculations to investigate structural, electronic, and optical properties of AgWO4 and PdWO4 tungstate materials for optoelectronic applications

Abstract

The optoelectronic devices play a crucial role in our daily lives by seamlessly integrating optics and electronics, enabling technologies like smartphones, solar cells, and optical communication. Solar cells have been very vital in terms of providing sustainable and clean energy. Conventional Perovskite-based solar cells possess limitations like stability and toxicity. Recently, ABO4-type materials have gained attention in optoelectronic devices due to their structural stability and suitable optoelectronic properties for solar cell applications. The structural, electronic, and optical properties of AgWO4 and PdWO4 have been explored using the first principal simulations in line with density functional theory (DFT) using WIEN2K simulation software. The Perdew-Burke-Ernzerhof Generalized-Gradient-Approximation (PBE-GGA) is acclimated to optimize the geometry of both materials under consideration. Trans-Balha modified Becke-Johnson approximation (TB-mBJ) approximation is implemented to study materials' optoelectronic properties. Structural analysis revealed the stable structure of AgWO4 and PdWO4 in the monoclinic phase with increasing lattice parameters and decreased unit cell volume upon replacement of Ag with Pd cation on the A site. Both materials ' negative values of ground state energies indicate the stability of both compounds. Upon analysis of the band structure of AgWO4 and PdWO4, it is found that both materials possess a band gap of 1.34eV and 0.73eV,respectively, signifying that both materials under consideration are semiconductors, with a potential for a controlled flow of electrical charges, coming up with promising various optoelectronic applications. Optical characteristics were explored and examined in depth in the framework of hypothetical dielectric constant. It has been discovered that the dielectric function has a broad span of energy integrity when it comes to its dielectric function. Materials with narrow bandgaps and excellent UV light absorption were found suitable for optoelectronic and solar cell applications.