Au-assisted growth of anisotropic and epitaxial cdse colloidal nanocrystals via in situ dismantling of quantum dots
KAUST DepartmentBiological and Environmental Sciences and Engineering (BESE) Division
Environmental Science and Engineering Program
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AbstractMetallic nanocrystals have been revealed in the past years as valuable materials for the catalytic growth of semiconductor nanowires. Yet, only low melting point metals like Bi have been reported to successfully assist the growth of elongated CdX (X = S, Se, Te) systems in solution, and the possibility to use plasmonic noble metals has become a challenging task. In this work we show that the growth of anisotropic CdSe nanostructures in solution can also be efficiently catalyzed by colloidal Au nanoparticles, following a preferential crystallographic alignment between the metallic and semiconductor domains. Noteworthy, we report the heterodox use of semiconductor quantum dots as a homogeneous and tunable source of reactive monomer species to the solution. The mechanistic studies reveal that the in situ delivery of these cadmium and chalcogen monomer species and the formation of AuxCdy alloy seeds are both key factors for the epitaxial growth of elongated CdSe domains. The implementation of this method suggests an alternative synthetic approach for the assembly of different semiconductor domains into more complex heterostructures.
SponsorsWe acknowledge financial support from the Spanish MINECO through CTQ2012-32247 and from the Generalitat de Catalunya through 2014 SGR 129. A.F. acknowledges the Spanish MINECO for a Ramon y Cajal Fellowship (RYC-2010-05821). V.F.-A. acknowledges the European Comission for the Career Development Allowance under the Marie Curie Programme (MRTN-CT-2005-019283). Some of the TEM experiments were carried out in the Scientific and Technological Centers of the University of Barcelona (CCiT-UB), with financial support of CSD2009-00013 and MAT2010-16407 Spanish research projects.
PublisherAmerican Chemical Society (ACS)
JournalChemistry of Materials