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We report scalable controlled synthesis of CdSe tetrapodswithhigh morphological uniformity based on the continuous precursor injection(CPI) approach with halide ligands. The CPI approach involves thesuccessive injection of precursors into the seed solution at a controlledrate so that the reaction condition remains in the kinetic growthregime. To initiate the successful development of tetrapod structure,the controlled amount of halide ligands are added during the reaction,which triggered the formation of wurtzite arms on {111}-facets ofthe zincblende seeds. The formation of the wurtzite phase is responsiblefor the halide-mediated displacement of oleate ligands, destabilizingthe embryonic CdSe phase on the zincblende seeds enabling the phasetransformation to more stable wurtzite phase on the hexagonal {111}-facets.On the basis of these halide-mediated phase transformation of CdSenanocrystals and the persistent kinetic growth induced by the CPIapproach, well-defined CdSe tetrapods with controlled arm length anddiameter have been produced in large quantity. [ABSTRACT FROM AUTHOR]

Growth of monodisperse indium phosphide (InP) quantum dots (QDs) represents a pressing demand in display applications, as size uniformity is related to color purity in display products. Here, we report the colloidal synthesis of InP QDs in the presence of Zn precursors in which size uniformity is markedly enhanced as compared to the case of InP QDs synthesized without Zn precursors. Nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, and mass spectrometry analyses on aliquots taken during the synthesis allow us to monitor the appearance of metal-phosphorus complex intermediates in the growth of InP QDs. In the presence of zinc carboxylate, intermediate species containing Zn-P bonding appears. The Zn-P intermediate complex with P(SiMe3)3 exhibits lower reactivity than that of the In-P complex, which is corroborated by our prediction based on density functional theory and electrostatic potential charge analysis. The formation of a stable Zn-P intermediate complex results in lower reactivity, which enables slow growth of QDs and lowers the extreme reactivity of P(SiMe3)3, hence monodisperse QDs. Insights from experimental and theoretical studies advance mechanistic understanding and control of nucleation and growth of InP QDs, which are key to the preparation of monodisperse InP-based QDs in meeting the demand of the display market. [ABSTRACT FROM AUTHOR]