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Preparation Of ZnSe Quantum Dots And Characterization Of Their Ring Distribution

Posted on:2017-06-30Degree:MasterType:Thesis
Country:ChinaCandidate:F D WangFull Text:PDF
GTID:2358330503471207Subject:Microelectronics and Solid State Electronics
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Quantum dots(QDs), with unique chemical and physical properties, are attention of people. In recent years, the QD is favored by researchers in biomedical field as for its superior performance. Compared with traditional organic dyes, QDs have narrow and symmetry emission spectrum, more stable fluorescent performance, and the same excitation light source can trigger different particle size of QDs emission fluorescence. ZnSe QD has a broadband gap, its fluorescence wavelength range is in blue-UV. The biological toxicity of ZnSe QD is lower compared with the Cd type QDs, more suitable for biomedical applications.First, this paper used the hydrothermal method at low temperature(105?) to synthesize ZnSe QDs. The preparation of QD belongs to cubic crystal system of ZnSe QDs confirmed by X-ray diffraction instrument. The use of fluorescence spectrometer analyzes the fluorescence properties of QDs which are synthesized by different experiment conditions. Results show that, ZnSe QDs have best fluorescent performance with water-soluble when the PH of 9,Se/Na2SO3 ratio of 1:2, TGA for 7ml, and ease of purification of QDs. In addition, UV modification method is adopted in the experiment to modifying the QD solution. With increasing of modification time, the near edge fluorescence emissions of QDs gradually red shift with the fluorescence intensity enhancement, and appear the defects emission peak at584 nm. In order to obtain better fluorescent property of ZnSe QD, this article also used the liquid paraffin-oleic acid system preparation of ZnSe QDs. By this method, the fluorescence intensity of ZnSe QDs is significantly higher than that of hydrothermal synthesis. By changing reaction conditions, such as the ZnSe QDs synthesis temperature, time of cladding,and ZnSe QDs synthesis time, observed the fluorescence intensity of ZnSe/ZnS QDs increased first and then decrease with the increase of reaction conditions. In the experiment,we can obtain best fluorescence performance of ZnSe/ZnS QDs under 170? to synthesize ZnSe QDs for 10 min, and then carries on the cladding 40 min. On the basis of the above experiments, ZnSe quantum ring are obtained by simple random method, and carries on the near-field characterization, observed the fluorescence intensity is stronger.
Keywords/Search Tags:ZnSe quantum dots, the hydrothermal method, the liquid paraffin-oleic acid system
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