The off-stoichiometry effect on the optical properties of water-soluble copper indium zinc sulfide quantum dots

Publication date: 15 June 2017
Source:Journal of Colloid and Interface Science, Volume 496
Author(s): Yanqiao Xu, Ting Chen, Xiaobo Hu, Wan Jiang, Lianjun Wang, Weihui Jiang, Jianmin Liu
CuInZnS quantum dots (CIZS QDs) were prepared via reflux method in aqueous solution using CuCl2·2H2O, InCl3·4H2O, Zn(OAc)2·2H2O and Na2S·9H2O as raw materials, l-glutathione (GSH) and sodiumcitrate (SC) as stabilizing agents, respectively. The effects of off-stoichiometry (Cu/In and Zn/Cu ratios) on the crystal structure and morphology were systematically studied by means of X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM), and the relative optical properties were also investigated by absorption and fluorescence spectra. The as-prepared water-dispersible CIZS QDs were around 3–4nm and possessed the tetragonal chalcopyrite crystal structure. The photoluminescence (PL) intensity of QDs was significantly increased with decreasing the Cu/In ratio. Compared with the Cu/In ratio variation, changing Zn/Cu ratio was an effective strategy to realize a more uniform irradiation and a wide range of emission wavelength tunability.

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