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Photoluminescence and XPS investigations of Cu 2+ ‐doped ZnS quantum dots capped with polyvinylpyrrolidone
Author(s) -
Hou Shili,
Zhang Xiangqiang,
Mao Huibing,
Wang Jiqing,
Zhu Ziqiang,
Jing Weiping
Publication year - 2009
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200844362
Subject(s) - photoluminescence , quantum dot , x ray photoelectron spectroscopy , analytical chemistry (journal) , luminescence , spectroscopy , materials science , aqueous solution , doping , auger electron spectroscopy , transmission electron microscopy , chemistry , nanotechnology , physics , nuclear magnetic resonance , optoelectronics , chromatography , quantum mechanics , nuclear physics
Cu 2+ ‐doped ZnS quantum dots were synthesized by a chemical precipitation method in water/ethanol solution. The quantum dots obtained were characterized by X‐ray diffraction, transmission electron microscopy and spectroscopy techniques including X‐ray photoelectron spectroscopy. The [S 2− ]/[Zn 2+ ] ratios have an effect on the photoluminescence of both aqueous solutions and powders of Cu 2+ ‐doped ZnS quantum dots. For aqueous samples, a green luminescence centre is observed in the spectrum of sample 1 with [S 2− ]/[Zn 2+ ] = 1:2 and a blue one for sample 2 with [S 2− ]/[Zn 2+ ] = 1:1. For powders, only the green emission is the main luminescence centre, and the integrated intensity in the blue emission region of sample 1 is stronger than that of sample 2. Compared with the spectrum of CuS powders, the X‐ray‐induced Auger electron spectrum of Cu L 3 M 45 M 45 in ZnS quantum dots shows a unique spectral characteristic. The 3d level of the Cu 2+ ion is split into two different energy levels at 334.0 and 347.2 eV, respectively.