| Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 94 === In this study, nano-sized CdSe particles were synthesized by the reverse micelle method, starting from Cd(NO3)2 and Na2SeSO3. Dioctyl sulfosuccinate sodium salt (AOT) was added as the surfactant. The effects of preparation conditions, such as W0 value, reaction temperature, [Cd2+]/[Se2-] ratio, concentrations of precursors and solvents, on the characteristics of prepared CdSe particles including the crystalline structure, particle size and size distribution were investigated. Furthermore, the ultraviolet absorption and photoluminescent properties of the particles were also studied.
The experimental results showed that the resulting CdSe nanoparticles synthesized by the reverse micelle method were are all fcc-structured. From the results of DLS and TEM observations, it was found that the prepared CdSe nanoparticles were stablely dispersed in the reverse micelles. Moreover, the size of CdSe particles decreased to a minimum as increasing the W0 value, reaction temperature, [Cd2+]/[Se2-] ratio and concentrations of precursors to their optima. Various solvents, i.e., cyclohexane, isooctane, hexane, heptane and dodecane were used for the study of solvent effect. The result showed that the CdSe nanoparticles synthesized in hexane system demonstrated the minimum particle size. It also revealed that the UV/VIS absorption and photoluminescence spectra were toward blue shift with decreasing the size of CdSe particles. Therefore, the bandgap of particles became larger.
In this study, the prepared CdSe particles were sizing from 5.4 to 3.3 nm which were corresponded to band gaps from 2.1 to 3.0 eV. In order to meet versatile applications, the bandgap of the prepared CdSe nanoparticles could be simply modulated by the preparation conditions in the reverse micelle system.
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