Impact of Zn alloying on structural, mechanical anisotropy, acoustic speeds, electronic, optical, and photocatalytic response of KMgF3 perovskite material

Abstract

This study explores the optoelectronic potential of advanced perovskite materials, with a primary focus on alloying KMgF3 with 3d transition metals. Through this alloying process, the study employs density functional theory (DFT) with the GGA-PBE functional to tailor the atomic structure and various properties, including optoelectronic, mechanical, acoustic, anisotropic, and photocatalytic attributes. The introduction of Zn to KMgF3 triggers a noticeable bandgap redshift and significant improvements in mechanical stability and photocatalytic performance. Increasing Zn content induces a transition in KMgF3's crystal structure to a pseudo-cubic tetragonal form, which remains mechanically stable for both pristine KMgF3 and KMg(1-x)ZnxF3. Zn inclusion introduces versatile nonlinearity in terms of brittleness, stiffness, mechanical strength, and thermal behavior. This comprehensive analysis underscores anisotropy, mixed bonding, Debye fluctuations, and melting temperature variations. Notably, among the systems examined, KMg0.25Zn0.75F3 stands out as an outstanding candidate for applications in photovoltaics and water splitting, thanks to its exceptional optical performance.