Controlled Synthese Of Ⅱ-Ⅵ Semiconductor Quantum Dots And The Study Of Optical Properies

Ⅱ-Ⅵ semiconductor nanocrystals, known as quantum dots (QDs). owing to the quantum confinement effect, QDs exhibit unique optical and physical properties, which decide they have an extraordinary high potential for applications in photovoltaic and biological applications. Among a number of possible synthesis strategies. high temperature(>300℃reaction-based organometallic chemistry is a traditional route to prepare the QDs, this method has disadvantages with regard to cost and toxicity. The use of a template is desirable to prepare the nanoparticles is water in oil(w/o) microemulsions also called reverse micelles. This method has some advantages, such as size-controlled, mild experimental conditions, simple operation and so on.In this thesis, AOT/water/isoctane reverse micelles were used to synthesis CdS QDs and Zn1-xCdxS QDs. The QDs with various sizes were synthesized by control changing the reaction temperature or the value of ω (ω=[H2O/[AOT]) in the microemulsion. The results were shown that the size of QDs are increased with the reaction temperature or the value of ω, and the quantum yield (QY), PL lifetime, PL emission and UV-absorbance of CdS QDs and Zn1-xCdxS QDs depend on the reaction temperature, the size of QDs and the composition X. The effects of the excition and emission wavelength, the molar ratios of thiol:CdS, the measure temperature and Cu2+,Ag+,Co2+ions on the PL properties were also studied.