Synthesis of CdZnSe Quantum Dots in Aqueous Phase by Microwave Irradiation

Recently many kinds of quantum dots were prepared by using microwave irradiation. Microwave irradiation provides rapid heating of polar substance and consequently results in faster, cleaner, and more efficient reactions than conventional heating process. In this study, alloyed CdZnSe quantum dots (QDs) have been synthesized in aqueous phase by microwave irradiation using 3-mercaptopropionic acid (MPA) as a stabilizer. Cd(NO3)(2), Zn(NO3)(2) and NaHSe were used as Cd, Zn and Se precursors, respectively. The process parameters such as Zn/Cd molar ratio, reaction pH and reaction time were varied to prepare CdZnSe QDs and photoluminescence (PL) dependence was studied. A strong PL emission peak was observed from the QDs prepared in weak acid conditions. As the reaction time increased, the absorbance spectra of the QDs were red shifted with increase of the intensity.