Synthesis of Heterostructure and Transition Metal Doped Quantum Dots
| Autor: | Jhe-Wei Yu, 余哲緯 |
|---|---|
| Rok vydání: | 2014 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 102 In this work, we have successfully synthesized the heterostructure quantum dots (HNS QDs) by the preformed seeded approaches. Cu2S or Ag2S nanocrystals was utilized as the seed crystals in the synthesis process of HNS QDs, and the secondary cation ion precursor was introduced into the preformed seed solution, followed by the cation exchange reaction. A number of capping agents have demonstrated good surface modification for the preparation of QDs. For example, capping agents could reduce the surface trap sites of QDs, avoid QDs’ aggregation and so on. For these insights, we adapted the various capping agents in the reaction system. The results revealed that a good optical performance of HNS QDs such as high quantum yields. Additionally, we also utilized the same formation mechanism to generate Cu2S-CdS HNS QDs and studied the related reaction mechanism. Furthermore, we synthesized the cation doped QDs by the common growth method. In this stage, CdS QDs was employed as the host QDs which could be doped with Cu (or Ag) cation. The results demonstrated that CdS host QDs did not initially show good optical tunable, however, Cu (or Ag) doped CdS QDs exhibit red-shift emission, showing from green (or yellow) to red orange (or orange) color. The structure and composition of the as-prepared QDs were characterized by the use of TEM, XRD, EDS, XPS, UV, PL, and ICP. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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