Synthesis of CdSe/ZnSe quantum dots passivated with a polymer for oxidation prevention

• Quantum dots synthesized using micro-reactor and subsequently applied PMMA coating
• The CdSe and CdSe/ZnSe are surface-oxidized, resulted in a reduction of stability.
• PMMA coated QDs improved dispersion and fluorescence stability.
• PMMA coating contributes to resist chemical degradation.

Surface overcoated CdSe/ZnSe core/shell structured quantum dots (QDs) with enhanced stability, narrow size distribution and strong photoluminescence have been successfully synthesized by using a simple poly(methylmethacrylate) (PMMA) coating on nanoparticles. When applied to the surface of QDs, the polymer coating provided ultra-dispersion stability and a high fluorescence quantum yield of above 80% that prevented chemical degradation, such as aggregation and Ostwald ripening. The degree of degradation was measured with respect to storage time (1, 7, 15, and 30 days) in order to provide a comparison between PMMA uncoated and coated QDs, and the oxidation of QDs was confirmed with Fourier transform infrared spectroscopy.