文章信息/Info

Title:

Preparation of CdSe and CdSe/ZnS Core-Shell Quantum Dots in Aqueous Phase

作者:

周蓓瑩; 王明輝; 江莞

東華大學材料科學與工程學院 纖維材料改性國家重點實驗室

Author(s):

ZHOU Beiying;  WANG Minghui;  JIANG Wan

State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University

關鍵詞:

CdSe量子點; CdSe/ZnS量子點; 核殼結構; 水相制備; 發光性能調控

Keywords:

CdSe QDs;  CdSe/ZnS QDs;  core-shell structure;  aqueous phase;  optical property control

DOI:

10.7502/j.issn.1674-3962.2017.05.10

文獻標志碼:

A

摘要:

因具有較寬的可調控發光范圍，CdSe量子點及其ZnS核殼結構量子點受到了研究者們的普遍關注。采用水相回流法合成了CdSe量子點及其ZnS核殼結構量子點，并結合透射電鏡(TEM)、X射線衍射(XRD)、紫外-可見光吸收光譜(UV-Vis)和熒光光譜(PL)對樣品進行表征。TEM結果表明，合成的量子點粒徑分布較寬且結晶度較高；從XRD分析結果可以看出，CdSe量子點為閃鋅礦結構，沿著晶面向外生長ZnS殼層后，譜峰向高角度偏移；從UV-Vis和PL分析結果可以看出，CdSe量子點于500 nm處出現吸收肩峰，于644 nm處出現半高寬較寬的缺陷發光峰；隨著反應時間的延長，于577 nm處出現本征發光峰。包覆了ZnS殼層后，量子點不僅發光強度明顯增大，而且穩定性顯著提高。該合成方法節能環保、生產效率高，具有較大的應用空間。

Abstract:

Due to the wide range of tunable emission peaks, CdSe quantum dots (QDs) and CdSe/ZnS core-shell QDs have attracted many attentions from researchers. Refluxing method was adopted to synthesize CdSe QDs and CdSe/ZnS core-shell QDs, and transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis absorption spectroscopy (UV-Vis) and photoluminescence spectra (PL) were used for characterization in this paper. The TEM images show that the size distribution of QDs is wide and the crystallinity is high. From the XRD spectra, it can be found that CdSe QDs possess zinc-blende structure, and the peak shifts to higher angle when ZnS shells are grown along the crystal plane by epitaxial growth method. From the UV-Vis and PL spectra of CdSe QDs, an absorption peak and a defect emission peak with large half width can be detected at 500 nm and 644 nm, respectively. With the refluxing time increasing, an intrinsic emission peak occurred at 577 nm. The ZnS outer layer can not only increase the luminescence intensity of CdSe QDs, but also further improve the stability. This synthesis method saves energy, possesses high production efficiency, friendly environmental protection, which has a larger application area.