Fragmentation of Magic‐Size Cluster Precursor Compounds into Ultrasmall CdS Quantum Dots with Enhanced Particle Yield at Low Temperatures. (11th May 2020)

• Record Type: Journal Article
• Authors: Li, Lijia; Zhang, Jing; Zhang, Meng; Rowell, Nelson; Zhang, Chunchun; Wang, Shanling; Lu, Jiao; Fan, Hongsong; Huang, Wen; Chen, Xiaoqin; Yu, Kui
• Is Part Of: Angewandte Chemie. Volume 132:Number 29(2020)
• Page Start: 12111
• Page End: 12119
• Publication Date: 2020-05-11
• Subjects: cadmium sulfide -- crystal growth -- magic-size clusters -- nucleation -- quantum dots; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202001608
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Colloidal small‐size CdS quantum dots (QDs) are produced usually with low particle yield, together with side products such as the particular precursor compounds (PCs) of magic‐size clusters (MSC). Here, we report our synthesis of small‐size CdS QDs without the coexistence of the PC and thus with enhanced particle yield. For a conventional reaction of cadmium oleate (Cd(OA)2 ) and sulfur (S) in 1‐octadecene (ODE), we show that after the formation of the PC in the pre‐nucleation stage, the addition of tri‐n‐octylphosphine oxide (TOPO) facilitates the production of small‐size QDs. We demonstrate that TOPO fragmentizes the PC that have formed, which enables the nucleation and growth of small‐size QDs even at room temperature. Our findings introduce a new approach to making small‐size QDs without the coexistence of the PC and with improved particle yield. Providing experimental evidence for the two‐pathway model proposed for the pre‐nucleation stage of colloidal binary QDs, the present study aids in the advance of non‐classical nucleation theory. Abstract : Small‐size CdS quantum dots are synthesized without the coexistence of the precursor compound and thus with enhanced particle yield. It is shown that after the formation of the precursor compound in the pre‐nucleation stage, the addition of tri‐n‐octylphosphine oxide facilitates the production of small‐size QDs.