High-yield synthesis of CsPbBr 3 nanoparticles: diphenylphosphine as a reducing agent and its effect in Pb-seeding nucleation and growth.

Based on the reported nucleation mechanisms for CsPbX 3 and II-VI/IV-VI quantum dots, CsPbBr 3 nanoparticles 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 CsPbBr 3 nanoparticles formation. Additionally, a clear influence of the DPP in a CsPbBr 3 -Cs 4 PbBr 6 incomplete phase transformation was observed, marked by the appearance of several PbBr 2 nanoparticles. 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 CsPbBr 3 nanoparticles showed high quality, as they displayed 70%-90% photoluminescence quantum yield; narrow size distribution with an average nanoparticle size of ∼ 10 nm; and the characteristic cubic morphology reported in previous works. This increment in CsPbBr 3 nanoparticles' reaction yield will contribute to making them a more attractive option for different optoelectronic applications.