Lead-Bromide Hybrid Perovskites with Different Dimensions due to NH₂ Position Variation Pyridine Ligand Methylene Bridge-CH₂

Abstract

The hybrid perovskites of amino(methyl) pyridines (AMP) and lead (II) bromide (PbBr2) were synthesised using a reflux method in 40% hydrobromic acid medium in a closed-nitrogen condition. The structural, chemical and optical properties of the as-synthesised compounds were analysed analytically using XRD, FT-IR and UV-Vis. Based on the XRD analysis, all compounds have distinct and evenly spaced diffraction peaks, indicating that they are strongly oriented and well-crystallised. The presence of aromatics and primary amines in mono-substituted pyridinium cation variations was confirmed by the FT-IR analysis. All compounds absorbed strongly in visible spectra at 430 nm, 427 nm and 355 nm, respectively. This study demonstrates that organic-tailoring effects in the shifting of aminomethyl position in the pyridine chain contribute to different dimensionalities of hybrid perovskite frameworks, even when synthesised under the same conditions. The as-synthesised low-dimensional hybrid perovskite can be further utilised as a light-harvester material in Perovskite Solar Cells (PSCs).