title: Small-angle rotation in individual colloidal CdSe quantum rods.
abstract: CdSe quantum rods (QRs) are very promising novel materials with unique electronic and optical properties. In this paper, we utilize a broad spectrum of techniques including high-resolution annular dark field scanning transmission electron microscope imaging, electron nanodiffraction, and computer simulations to study the internal structure of individual QRs. Random small-angle rotations are commonly found between various sections within individual QRs which can be resolved into twists around the c-axis and bends. The possible origins of these small-angle rotations are further studied. We propose that imperfect oriented attachment coupled with electrostatic interactions between smaller nanoparticles during the growth process results in such small-angle rotations. These small-angle rotations may significantly affect the electronic and mechanical properties of CdSe QRs.
authors.affiliation: Physics Department, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Yu
authors.forename: Megan A
authors.initials: MA
authors.lastname: Hahn
authors.forename: Sara E
authors.initials: SE
authors.lastname: Maccagnano-Zacher
authors.forename: Joaquin
authors.initials: J
authors.lastname: Calcines
authors.forename: Todd D
authors.initials: TD
authors.lastname: Krauss
authors.forename: Erik S
authors.initials: ES
authors.lastname: Alldredge
authors.forename: John
authors.initials: J
authors.lastname: Silcox
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003198:Computer Simulation; D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012399:Rotation; D018036:Selenium Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D019187:Cadmium Compounds; D046911:Macromolecular Substances; D018036:Selenium Compounds; C058667:cadmium selenide