Dipolar structures in colloidal dispersions of PbSe and CdSe quantum dots.
We show by cryogenic transmission electron microscopy that PbSe and CdSe nanocrystals of various shapes in a liquid colloidal dispersion self-assemble into equilibrium structures that have a pronounced dipolar character, to an extent that depends on particle concentration and size. Analyzing the cluster-size distributions with a one-dimensional (1D) aggregation model yields a dipolar pair attraction of 8-10 kBT at room temperature. This accounts for the long-range alignment of the crystal planes of individual nanocrystals in self-assembled superstructures and for anisotropic nanostructures grown via oriented attachment.
Klokkenburg
Mark
M
Van 't Hoff Laboratory for Physical and Colloid Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
Houtepen
Arjan J
AJ
Koole
Rolf
R
de Folter
Julius W J
JW
Erné
Ben H
BH
van Faassen
Ernst
E
Vanmaekelbergh
Daniël
D
D019187:Cadmium Compounds / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D007854:Lead / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry*; D013499:Surface Properties
D019187:Cadmium Compounds; D003102:Colloids; D046911:Macromolecular Substances; D018036:Selenium Compounds; C088065:lead selenide; D007854:Lead; C058667:cadmium selenide