Understanding the optical and bonding properties of hybrid metal-halide (C5H16NP) PbX4 (X = Cl, Br, I) perovskite: A density-functional theory study

Abstract Hybrid perovskites have demonstrated high stability and a promising optoelectronic performance for solar-cells. The quest over their functionalities beyond photo-voltaic applications is currently an important challenge. In this work, we have used density-functional theory to study hybrid perovskites. In particular, we have explored how atomic substitution could be used to design their optoelectronic properties. Under this approach, we have investigated the effect of changing the halogen atom (X  = Cl, Br, I) on the structural, electronic, and optical properties of (C5H16NP) PbX4 hybrid perovskites. The electronic properties have been computed using hybrid functionals including the spin–orbit coupling, showing a good agreement with previous experiments. We have also shown that tuning the halogen atom changes the band gap, allowing us to find an optimal value for ultraviolet–visible devices. We will highlight the role of the octahedral [PbX6]2− units, chemical bonding, and non-covalent interactions on the structural stability and optoelectronic properties. This study reveals that halogen substitutions will infer enhanced resonances in the ultraviolet domain, making (C5H16NP) PbX4 good candidates for 2D/3D layered photo-responsive stacked devices.