Preparation of Nano-sized CdS Particles by Microwave Heating Method and Preparation of CdS Thin Films by Electrospraying Method
| Autor: | Chuan-Wen Lin, 林全雯 |
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| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 Light-emitting diodes (LEDs) have the advantages of small volume, long lifetime, no mercury pollution, low energy loss, and high emission efficiency. Developments of LEDs not only serve to improve the disadvantages of traditional illuminants but also save the energy and protect the environment of the world. In the study, CdS nanoparticles are synthesized by sol-gel method assisted with microwave heating. The microwave assisted heating has been used to control the nucleation rate and growth rate of nanoparticles. Stable colloidal CdS solution was prepared using DMF as solution. We study the influence of reaction temperature, precursor concentration and solvent on the size of CdS nanoparticles. CdS thin films were prepared by electrospraying CdS particles contained solution with the assistance of an electrostatic collector. Particles of a specific diameter were collected for a specific voltage according to their mobility. The size of nanoparticles was analyzed by TEM. Optical properties of CdS nanoparticles were observed with UV and PL spectrometer. Thin film morphology was analyzed by SEM. Using microwave heating to prepare nanoparticles is a simple, safe and easy to control. The experimental results show that the smallest CdS nanoparticle size is 2.6nm. CdS thin films with a grain size less than 5nm wrer prepared with the assistance of electrostatic collector. The results show that the thin films were not very compact and the particle size is larger than we set to collect. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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