Effects of oleylamine concentration on the synthesis of formamidinium lead halide perovskite nanocrystals and physical-optical properties

Perovskite nanocrystals (PNCs) has been extensively interested owing to their distinctive properties for applications in optoelectronics and energy harvesting. The properties of these nanocrystals, including optical and energy characteristics, can be tuned by adjusting the particle size using different synthesis techniques. Among these, the ligand-assisted reprecipitation (LARP) method has become popular for its simplicity and scalability. Nevertheless, it is vital to understand that the growth of PNCs is extremely sensitive to the conditions of synthesis, highlighting the importance of recognizing the factors that limit the formation and properties of PNCs. In this study, PNCs based on formamidinium lead bromide (FAPbBr3) were synthesized via the LARP method under room temperature and ambient atmospheric conditions. The structures and optical properties, including photoluminescence lifetime, of PNCs with varying amounts of organic ligands were investigated. Transmission electron microscopy showed that high concentrations of organic ligands lead to the formation of perovskite clusters. We also noted a slight red shift in the photoluminescence peak as the size of the PNCs increased. A peak photoluminescence quantum yield (PLQY) of 74% was achieved. This study provides crucial insights into the effects of ligand ratios and serves as a valuable resource for refining the synthesis parameters of PNCs.