Search for Efficient Absorber Materials from <i>A</i>₂<i>B</i> Binary Compounds: A Comprehensive Computational Modeling Approach

Motivated by the pursuit of environmentally friendly energy, this study explores the intriguing world of four chalcogenide-based binary compounds Cs2Se, Cs2Te, Rb2Se, and Rb2Te. We tried to investigate their unexplored properties using computational methods, preparing the way for potentially ground-breaking solar cell applications. Based on density functional theory, the present study used the Cambridge serial total energy package code to figure out the structural, mechanical, and optoelectronic properties of A2B compounds (where A = Cs, Rb and B = Se,Te). The computed band gaps, total density of states, and partial density of states of these binary compounds under consideration confirm the semiconductor behavior. The results show that these four compounds are mechanically and thermodynamically stable. They absorb light more strongly in the ultraviolet and visible regions and are direct and indirect band-gap semiconductors, which can be potential photodetector materials. We have analyzed the solar cell capabilities by calculating the thickness dependence spectroscopic limited maximum efficiency of the active layers using the SLME python package to scrutinize the most efficient absorber layer. Besides this, we have computed the effective mass, carrier mobility, diffusion length, and diffusion constant for electrons and holes of all four materials. Furthermore, we have carried out numerical-based device simulations of these four solar cells using A2B as one of the active layers, with Rb2Te as the highest efficient layer.