کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
739220 1461635 2014 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photoluminescence and upconversion on Ag/CdTe quantum dots
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی برق و الکترونیک
پیش نمایش صفحه اول مقاله
Photoluminescence and upconversion on Ag/CdTe quantum dots
چکیده انگلیسی


• Different sizes of CdTe QDs by using a Microwave irradiation method were prepared.
• Enhancement and quenching behaviors of Ag/CdTe were investigated.
• Upconversion photoluminescence in CdTe at low excitation intensity was observed.
• Our findings are promising candidates for photonic devices.

Different sizes of aqueous CdTe QDs have been prepared by microwave via controlling the temperature and time of irradiation. To study the plasmonic effect on CdTe QDs, Silver NPs were prepared by using a chemical reduction method. Structure characterization of the nanocrystals (Ag NPs and CdTe QDs) was determined by transmission electron microscopy “TEM”. For optical characterization, the absorption and photolumincence (PL) spectra were measured. It has been found that there are two opposite behaviors (quenching and enhancement) in the fluorescence spectra based on the spectral coupling strength between Ag NPs and CdTe QDs. When there is strong overlapping, PL enhancement of CdTe QDs has been observed. On the other hand, when the overlapping is weak, the PL quenching was predominant at all Ag NPS concentrations. Input–output PL intensity dependence was also studied. Upconversion photoluminescence with low excitation intensity was observed in our CdTe QDs with a standard spectrofluorometer at excitation wavelength of 800 nm. Thermally assisted surface state mechanism has been proposed to be responsible for the upconverion process.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optics & Laser Technology - Volume 63, November 2014, Pages 8–12
نویسندگان
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