title: Aqueous synthesis of zinc blende CdTe/CdS magic-core/thick-shell tetrahedral-shaped nanocrystals with emission tunable to near-infrared.
abstract: We demonstrate the synthesis of near-IR-emitting zinc blende CdTe/CdS tetrahedral-shaped nanocrystals with a magic-sized (approximately 0.8 nm radius) CdTe core and a thick CdS shell (up to 5 nm). These high-quality water-soluble nanocrystals were obtained by a simple but reliable aqueous method at low temperature. During the growth of the shell over the magic core, the core/shell nanocrystals change from type I to type II, as revealed by their enormous photoluminescence (PL) emission peak shift (from 480 to 820 nm) and significant increase in PL lifetime (from approximately 1 to approximately 245 ns). These thick-shell nanocrystals have a high PL quantum yield, high photostability, compact size (hydrodynamic diameter less than 11.0 nm), and reduced blinking behavior. The magic-core/thick-shell nanocrystals may represent an important step toward the synthesis and application of next-generation colloidal nanocrystals from solar cell conversion to intracellular imaging.
authors.affiliation: The Biodesign Institute, Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA. zhengtao.deng@asu.edu
authors.forename: Zhengtao
authors.initials: Z
authors.lastname: Deng
authors.forename: Olaf
authors.initials: O
authors.lastname: Schulz
authors.forename: Su
authors.initials: S
authors.lastname: Lin
authors.forename: Baoquan
authors.initials: B
authors.lastname: Ding
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Liu
authors.forename: XiXi
authors.initials: X
authors.lastname: Wei
authors.forename: Robert
authors.initials: R
authors.lastname: Ros
authors.forename: Hao
authors.initials: H
authors.lastname: Yan
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D019187:Cadmium Compounds / Q000138:chemical synthesis*; D007259:Infrared Rays; D008163:Luminescent Measurements; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry*; D012666:Semiconductors; D013440:Sulfides / Q000138:chemical synthesis*; D013691:Tellurium; D013696:Temperature; D014867:Water / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D014867:Water; D015032:Zinc; D013691:Tellurium; C028337:cadmium telluride