کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5404399 | 1505933 | 2006 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Significant enhancement of the quantum yield of CdTe nanocrystals synthesized in aqueous phase by controlling the pH and concentrations of precursor solutions
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
In this paper, we systematically investigated the aqueous synthesis conditions of CdTe nanocrystals (QDs), and found that the pH value and the concentrations of precursors significantly affected the photoluminescence quantum yield (QY) of CdTe QDs. When the concentration of precursors (Cd) was 1.25Â mM, and the pH of Cd precursors solution was about 8.0, CdTe QDs with high QY up to 40-67% were successfully prepared in aqueous phase. Moreover, these high luminescent QDs showed excellent stabilities in aqueous phases, and their luminescence was nearly independent of the pH of the colloid solution. The XPS and XRD characterizations implied that the high luminescence of the QDs synthesized at lower pH was possibly attributed to the formation of the thicker shell (cadmium-3-mercaptopropionic acid complexes) on particles surface, which not only decreased the traps on QDs surface, but also acted as a steric barrier to control the kinetics of QDs growth and led to the formation of a better surface structure. Our modification of conventional aqueous synthesis dramatically improved the QY of the prepared CdTe QDs, and it will become an attractive alternative to the synthesis of QDs in organic phase.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 116, Issues 1â2, JanuaryâFebruary 2006, Pages 59-66
Journal: Journal of Luminescence - Volume 116, Issues 1â2, JanuaryâFebruary 2006, Pages 59-66
نویسندگان
Liang Li, Huifeng Qian, Nenghu Fang, Jicun Ren,