Preparation and characterization of CdSe quantum dots/poly (amido amine) dendrimer nano-composites

Uniform, well-dispersed and strong photoluminescent CdSe quantum dots(QDs) were prepared taking poly(amido amine)(PAMAM) dendrimers as inner templates in water with NaHSe as Se resources. The properties of CdSe QDs encapsulated in dendrimers were characterized by UV-Vis absorption spectra, photoluminescence(PL) emission spectra and high resolve transmission electron microscope(HRTEM). The results were: strong interface charge transfer function happens between dendrimers and CdSe QDs when irradiated under UV light. Amine-terminated dendrimers protoned and high-generation dendrimers were better templates compared with carboxylate-terminated and low-generation dendrimers. The stability, diameter and PL efficiency of CdSe QDs were affected remarkably by pH and temperature and the proper condition was neutral and 0°C. CdSe QDs with different diameters and photoluminescence colors were prepared by changing the mole ratio of Cd²⁺ to PAMAM dendrimers.