High-yield synthesis of CsPbBrnanoparticles: diphenylphosphine as a reducing agent and its effect in Pb-seeding nucleation and growth.

Based on the reported nucleation mechanisms for CsPbXand II-VI/IV-VI quantum dots, CsPbBrnanoparticles with a higher reaction-yield (up to 393% mass-increment) were synthetized by the hot-injection method. The introduction of diphenylphosphine (DPP) as a reducing agent improved nanoparticle nucleation and growth, giving out evidence for Pb-seeding in CsPbBrnanoparticles formation. Additionally, a clear influence of the DPP in a CsPbBr-CsPbBrincomplete phase transformation was observed, marked by the appearance of several PbBrnanoparticles. This indicated the need for an improved ratio between the stabilizing agents and the precursors, due to the increased number of nucleation sites produced by DPP. The resulting CsPbBrnanoparticles showed high quality, as they displayed 70%-90% photoluminescence quantum yield; narrow size distribution with an average nanoparticle size of10 nm; and the characteristic cubic morphology reported in previous works. This increment in CsPbBrnanoparticles' reaction yield will contribute to making them a more attractive option for different optoelectronic applications.