Precursor reaction kinetics control compositional grading and size of CdSe_1-x S _x nanocrystal heterostructures.

ABSTRACT: We report a method to control the composition and microstructure of CdSe_1-x S _x nanocrystals by the simultaneous injection of sulfide and selenide precursors into a solution of cadmium oleate and oleic acid at 240 °C. Pairs of substituted thio- and selenoureas were selected from a library of compounds with conversion reaction reactivity exponents (k _E) spanning 1.3 × 10^-5 s^-1 to 2.0 × 10^-1 s^-1. Depending on the relative reactivity (k _Se/k _S), core/shell and alloyed architectures were obtained. Growth of a thick outer CdS shell using a syringe pump method provides gram quantities of brightly photoluminescent quantum dots (PLQY = 67 to 90%) in a single reactio

SUBMITTER: Hamachi LS 

PROVIDER: S-EPMC6615248 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature