Preparation and Characterization of Polymer-CdSe/ZnS QDs Composite Thin Film

doi:10.3724/SP.J.1077.2010.00700

Abstract

Abstract:

High quality water-soluble semiconductor CdSe/ZnS quantum dots (QDs) were prepared by a phase transfer method, in which amphiphilic oligomers (polymaleic acid n-hexadecanol alcohol ester, PMAH) was used as surface coating agents. The as-prepared aqueous QDs were high fluorescent and extremely stable. To form the composite emulsion, different concentration of water-soluble CdSe/ZnS QDs was dispersed in PAA emulsion. The polymer-CdSe/ZnS QDs composite thin film was then fabricated using the composite emulsion with a spin-coating method. The obtained CdSe/ZnS QDs composite thin film was transparent under sun light and had bright red light under the irradiation of UV light. The composite thin film was also characterized with X-ray Photoelectron Spectroscopy. The photoluminescence (PL) property and tolerance to UV light of the thin film were also characterized in dark circumstances. The PL intensity of the film showed increment with the increase of layer number and the concentration of CdSe/ZnS QDs within each film. Furthermore, the composite film retained its high quantum yield (QY) with only 5% QY lost after UV irradiation for 800 h.

Key words: CdSe/ZnS QDs, composite thin film, preparation

CLC Number:

O647

ZHOU Chang-Hua, WANG Xin, SHEN Huai-Bin, LI Lin-Song, CHEN Jian-Min. Preparation and Characterization of Polymer-CdSe/ZnS QDs Composite Thin Film[J]. Journal of Inorganic Materials, 2010, 25(7): 700-704.

References

[1]Bruchez M, Moronne M, Gin P, et al. Semiconductor nanocrystals as fluorescent biological labels. Science, 1998, 281(5385): 2013-2016.
[2]Chan W C, Nie S. Quantum dot bioconjugates for ultrasensitive nonisotopic detection. Science, 1998, 281(5385): 2016-2018.
[3]Algar W R, Krull U J. Luminescence and stability of aqueous thioalkyl acid capped CdSe/ZnS quantum dots correlated toligand ionization. Chem. Phys. Chem., 2007, 8(4): 561-568.
[4]Han M, Gao X, Su J Z, et al. Quantum-dot-tagged microbeads for multiplexed optical coding of biomolecules. Nat. Biotechnol., 2001, 19(7): 631-635.
[5]Michalet X, Pinaud F F, Bentolila L A, et al. Quantum dots for live cells, in vivo imaging, and diagnostics. Science, 2005, 307(5709): 538-544.
[6]Medintz I L, Uyeda H T, Goldman E R, et al. Quantum dot bioconjugates for imaging,labelling and sensing. Nat. Mater., 2005, 4(6): 435-446.
[7]Decher G. Fuzzy Nanoassemblies: toward layered polymeric multicomposites. Science, 1997, 277(5330): 1232-1237.
[8]Clark S L, Hammond P T. Engineering the microfabrication of layer-by-layer thin films. Adv. Mater., 1998, 10(18): 1515-1519.
[9]Sun J, Hao E, Sun Y, et al. Multilayer assemblies of colloidal ZnS doped with silver and polyeletrolytes based on electrostatic interaction. Thin solid films, 1998, 327-329: 528-531.
[10]Kotov N A, Dekany I, Fendler J H. Layer-by-layer self-assembly of polyelectrolyte-semiconductor nanoparticle composite films. J. Phys. Chem., 1995, 99(35): 13065-13069.
[11]刘明贤, 孙颖, 甘礼华, 等(LIU Ming-Xian, et al). 静电自组装制备CdTe 量子点薄膜. 无机材料学报 (Journal of Inorganic Materials), 2008, 23(3): 557-561.
[12]凌剑, 丛日敏 (LING Jian, et al). 以CdS-ZnS 核-壳量子点/聚酰胺-胺(PAMAM)树形分子纳米复合材料自组装制备发光超薄膜. 化学学报 (Acta Chim. Sinica), 2008, 66(18): 2070-2074.
[13]Wang J Y, Chen W, Liu A H, et al. Controlled fabrication of cross-linked nanoparticles/polymer composite thin films through the combined use of surface-initiated atom transfer radical polymerization and gas/solid reaction. J. Am. Chem. Soc., 2002, 124(45): 13358-13359.
[14]Zhang H, Cui Z C, Wang Y, et al. From water-soluble CdTe nanocrystals to fluorescent nanocrystal-polymer transparent composites using polymerizable surfactants. Adv. Mater., 2003, 15(10): 777-780.
[15]Shen H B, Wang H Z, Tang Z J, et al. High quality synthesis of monodisperse zinc-blende CdSe and CdSe/ZnS nanocrystals with a phosphine-free method. Cryst. Eng.Comm., 2009(11): 1733-1738.
[16]李林松, 周长华, 申怀彬, 等. 一种水溶性纳米晶的制备方法. 中国专利, 发明专利, 200810049951. 2008.12.10.