title: Crystal structure control of zinc-blende CdSe/CdS core/shell nanocrystals: synthesis and structure-dependent optical properties.
abstract: Nearly monodisperse zinc-blende CdSe/CdS core/shell nanocrystals were synthesized by epitaxial growth of 1-6 monolayers of CdS shell onto presynthesized zinc-blende CdSe core nanocrystals in one pot. To retain the zinc-blende structure, the reaction temperature was lowered to the 100-140 °C range by using cadmium diethyldithiocarbamate as a single-source precursor and primary amine as activation reagents for the precursor. Although the wurtzite counterparts grown under the same conditions showed optical properties similar to those reported in the literature, zinc-blende CdSe/CdS core/shell nanocrystals demonstrated surprisingly different optical properties, with ensemble single-exponential photoluminescence decay, significant decrease of photoluminescence peak width by the shell growth, and comparatively high photoluminescence quantum yields. The lifetime for the single-exponential ensemble photoluminescence decay of zinc-blende CdSe/CdS core/shell nanocrystals with 3-4 monolayers of CdS shell was reproducibly found to be approximately 16.5 ± 1.0 ns.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Wennuan
authors.initials: W
authors.lastname: Nan
authors.forename: Yuan
authors.initials: Y
authors.lastname: Niu
authors.forename: Haiyan
authors.initials: H
authors.lastname: Qin
authors.forename: Fan
authors.initials: F
authors.lastname: Cui
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Runchen
authors.initials: R
authors.lastname: Lai
authors.forename: Wanzhen
authors.initials: W
authors.lastname: Lin
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Peng