Facet to Facet Linking of Shape Anisotropic Inorganic Nanocrystals with Site Specific and Stoichiometric Control.
Nonclassical growth mechanisms such as self-assembly and oriented attachment are effective ways to build complex nanostructures from simpler ones. In the latter case, the nanoparticle components are electronically coupled; however, control over the attachment between nanoparticles is highly challenging and generally requires a delicate balance between dipole-, ligand-, and solvent-based interactions. To this end, we perform incomplete cation exchange with Ag+(Cu+) on CdSe-seeded CdS nanorods and tetrapods to exclusively convert their tips into small Ag2S (Cu2S) domains. Selective removal of the ligands from these inorganic domains results in spontaneous, site-specific bridging of the nanoparticles. Using this method, we demonstrate the fabrication of polymer-like linear and branched nanoparticles with enhanced electrical properties, as well as the stoichiometric formation of nanoparticle homo- and heterodimers and tetramers. We show that linked structures can then be completely cation exchanged with Pb2+to generate PbSe/PbS-based nanostructured photodetector media with enhanced properties.
Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
Sabyasachi
S
Chakrabortty
Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
Asim
A
Guchhait
Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
Xuanwei
X
Ong
Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.
Nimai
N
Mishra
Institute of Materials Research & Engineering, A*STAR , 2 Fusionopolis Way. Innovis, #08-03, Singapore 138634, Singapore.
Wen-Ya
WY
Wu
Institute of High Performance Computing, A*STAR , 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore.
Mark Hyunpong
MH
Jhon
Department of Chemistry, National University of Singapore , 3 Science Drive 3, Singapore 117543, Singapore.|Institute of Materials Research & Engineering, A*STAR , 2 Fusionopolis Way. Innovis, #08-03, Singapore 138634, Singapore.|Microfluidics Systems Biology Lab, Institute of Molecular and Cell Biology, A*STAR , 61 Biopolis Drive, Singapore 138673, Singapore.
Yinthai
Y
Chan
Nanoparticle assembly; cation exchange; facet engineering; photodetector; semiconductor nanoheterostructures