A Dual Emissive BODIPY Dye and Its Use in Functionalizing Highly Monodispersed PbS Nanoparticles

摘要

BODIPY (boron-dipyrromethene) dyes and derivatives are well-known to be very effective in light-harvesting and energy-transfer processes, owing to their high fluorescence quantum yields, large molar absorption coefficients, relatively long excited-state lifetimes, and excellent photochemical stability. Thus, they have frequently been used in light-harvesting molecules, as dye sensitizers, and as probes and labels for biomolecules. One important class of materials for various optoelectronic applications, including solar cells, is the class of semiconductor nanoparticles (NPs). The optical and energetic properties of these nanoparticles can be tuned by varying their shape, size, or surface ligands. Lead sulfide NPs are particularly attractive among NPs owing to their narrow band gap, large exciton Bohr radii, and their absorption and emission in the near-IR region. Several recent reports have shown that PbS NPs are very promising materials for achieving high-performance photovoltaic devices. The most commonly used surface ligand for PbS NPs is oleic acid, which can effectively protect the NPs from oxidation and can facilitate their dispersion in organic solvents.However, because they lack any interesting photophysical properties, oleic acid capping ligands do not engage in any electronic communication or interactions with the NPs and thus have little influence on the properties of the NPs and insulate NPs from each other and the surrounding medium. New surface ligands that can communicate electronically with PbS NPs and enhance their performance in optoelectronic devices are therefore in demand. Based on this consideration and the very attractive photophysical proper- ties of BODIPY dyes, we initiated the investigation of new BODIPY dyes as potential new surface ligands for PbS NPs. Herein, we report the synthesis and photophysical properties of a new BODIPY dye (BDY) and its use in PbS NPs functionalization.