title: Alloyed copper chalcogenide nanoplatelets via partial cation exchange reactions.
abstract: We report the synthesis of alloyed quaternary and quinary nanocrystals based on copper chalcogenides, namely, copper zinc selenide-sulfide (CZSeS), copper tin selenide-sulfide (CTSeS), and copper zinc tin selenide-sulfide (CZTSeS) nanoplatelets (NPLs) (∼20 nm wide) with tunable chemical composition. Our synthesis scheme consisted of two facile steps: i.e., the preparation of copper selenide-sulfide (Cu2-xSeyS1-y) platelet shaped nanocrystals via the colloidal route, followed by an in situ cation exchange reaction. During the latter step, the cation exchange proceeded through a partial replacement of copper ions by zinc or/and tin cations, yielding homogeneously alloyed nanocrystals with platelet shape. Overall, the chemical composition of the alloyed nanocrystals can easily be controlled by the amount of precursors that contain cations of interest (e.g., Zn, Sn) to be incorporated/alloyed. We have also optimized the reaction conditions that allow a complete preservation of the size, morphology, and crystal structure as that of the starting Cu2-xSeyS1-y NPLs. The alloyed NPLs were characterized by optical spectroscopy (UV-vis-NIR) and cyclic voltammetry (CV), which demonstrated tunability of their light absorption characteristics as well as their electrochemical band gaps.
authors: Department of Nanochemistry, Istituto Italiano di Tecnologia , via Morego, 30, 16163 Genova, Italy.
authors: Vladimir
authors: V
authors: Lesnyak
authors: Chandramohan
authors: C
authors: George
authors: Alessandro
authors: A
authors: Genovese
authors: Mirko
authors: M
authors: Prato
authors: Alberto
authors: A
authors: Casu
authors: S
authors: S
authors: Ayyappan
authors: Alice
authors: A
authors: Scarpellini
authors: Liberato
authors: L
authors: Manna