Back to Search Start Over

Synthesis of Air-Stable CdSe/ZnS Core-Shell Nanoplatelets with Tunable Emission Wavelength.

Authors :
Polovitsyn, Anatolii
Zhiya Dang
Movilla, José L.
Martín-García, Beatriz
Khan, Ali Hossain
Bertrand, Guillaume H. V.
Brescia, Rosaria
Moreels, Iwan
Source :
Chemistry of Materials. Jul2017, Vol. 29 Issue 13, p5671-5680. 10p.
Publication Year :
2017

Abstract

In the past few years, several protocols have been reported on the synthesis of CdSe nanoplatelets with narrow photoluminescence (PL) spectrum, high PL quantum efficiency, and short exciton lifetime. The corresponding core/shell nanoplatelets are however still mostly based on CdSe/CdS, which possess an extended lifetime and a strong red shift of the band-edge absorption and emission, in accordance with a quasi-type-II band alignment. Here we report on a robust synthesis procedure to grow a ZnS shell around CdSe nanoplatelets at moderate temperatures of 100-150 °C, to improve the optical properties of CdSe nanoplatelets via a type-I core/shell heterostructure. The shell growth is performed under ambient atmosphere, in either toluene or 1,2-dichlorobenzene. The variation of the shell thickness induces a continuous red shift of the PL peak, eventually reaching 611 nm. The PL quantum efficiency is increased compared to the original CdSe cores, with values up to 60% depending on the shell thickness. High-resolution transmission electron microscopy reveals a bending of the nanoplatelets caused by strain due to 12% lattice mismatch between CdSe and ZnS. The present procedure can easily be translated to other core/shell nanocrystals, such as CdSe/CdS and CdSe/CdZnS nanoplatelets. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
08974756
Volume :
29
Issue :
13
Database :
Academic Search Index
Journal :
Chemistry of Materials
Publication Type :
Academic Journal
Accession number :
124098540
Full Text :
https://doi.org/10.1021/acs.chemmater.7b01513