关键词: 纳米薄膜, CdTe量子点, 静电自组装, 荧光

Abstract: Negatively charged and monodisperse CdTe quantum dots (QDs) with average size of about 5nm were synthesized in aqueous solution using 3-mercaptopropionic acid as stabilizing reagent. Through the electrostatic interactions among the negative surface charges on CdTe QDs, the cationic groups of poly(diallyldimethylammonium chloride) (PDDA) and the anionic groups of poly(sodium 4-styrene-sulfonate) (PSS), ultrathin multilayer of CdTe QDs were fabricated on the pretreated quartz substrate by layer-by-layer electrostatic self-assembly method. UV-Vis spectra, photoluminescence spectra, XPS and AFM were used to characterize the ultrathin films. The results show that there is a linear relationship between the adsorption and the layer numbers of the thin films, indicating that the resultant nanofilms have good quality. The ultrathin films are flatly deposited on the quartz surface with some aggregates of CdTe QDs on it.
The stability and quality of the films can be improved by the introduction of polyelectrolyte multilayers of PDDA/PSS/PDDA between two adjacent layers of CdTe QDs on the substrate. The prepared ultrathin films of CdTe QDs show good photoluminescence property.