Open Access Nano Express

Facile Synthesis of Monodisperse CdS Nanocrystals via Microreaction

Zhen Wan1, Hongwei Yang1, Weiling Luan1*, Shan-tung Tu1 and Xinggui Zhou2

Author Affiliations

1 State Key Laboratory of Safety Science of Pressurized System, School of Mechanical and Power Engineering, East China University of Science and Technology, 200237, Shanghai, China

2 State Key Laboratory of Chemical Engineering, East China University of Science and Technology, 200237, Shanghai, China

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Nanoscale Research Letters 2009, 5:130-137  doi:10.1007/s11671-009-9454-z

Published: 13 October 2009

Abstract

CdS-based nanocrystals (NCs) have attracted extensive interest due to their potential application as key luminescent materials for blue and white LEDs. In this research, the continuous synthesis of monodisperse CdS NCs was demonstrated utilizing a capillary microreactor. The enhanced heat and mass transfer in the microreactor was useful to reduce the reaction temperature and residence time to synthesize monodisperse CdS NCs. The superior stability of the microreactor and its continuous operation allowed the investigation of synthesis parameters with high efficiency. Reaction temperature was found to be a key parameter for balancing the reactivity of CdS precursors, while residence time was shown to be an important factor that governs the size and size distribution of the CdS NCs. Furthermore, variation of OA concentration was demonstrated to be a facile tuning mechanism for controlling the size of the CdS NCs. The variation of the volume percentage of OA from 10.5 to 51.2% and the variation of the residence time from 17 to 136 s facilitated the synthesis of monodisperse CdS NCs in the size range of 3.0–5.4 nm, and the NCs produced photoluminescent emissions in the range of 391–463 nm.

Keywords:
Microreaction; Quantum dots; CdS; Nanocrystals