Photostability of the Oleic Acid-Encapsulated Water-Soluble Cd_xSe_yZn_1-xS_1-y Gradient Core-Shell Quantum Dots

Summary, in English

Composite systems where quantum dots (QDs) are combined with other nanomaterials (e.g., gold nanorods) in aqueous solutions have attracted broad attention - both for their potential in applications and for studies of fundamental processes. However, high-quality QDs are typically prepared in organic solvents, and the transfer of QDs to an aqueous phase is needed to create the desired QD composites. Photostability of the transferred QDs - both the steady-state and photo-induced dynamic properties - is essential for studying the processes in the composites and for their applications. We present a detailed study of the photostability of aqueous Cd_xSe_yZn_1-xS_1-y gradient core-shell QDs obtained by various approaches using linker exchange and surfactant encapsulation. Beside the steady-state photoluminescence (PL) emission stability, we also study changes in the PL decay. From the variety of the studied samples, the water-soluble QDs encapsulated by a double layer of oleic acid show superior properties, that is, stable PL emission and PL decay under continuous light or pulsed-laser light irradiation. We demonstrate that the double-layer encapsulation of QDs can be used to create QDs-metal nanoparticle composites.

• Author: Junsheng Chen; B Yang; Chuanshuai Li; Kaibo Zheng; Karel Zidek; Tonu Pullerits
• Department/s: Chemical Physics; NanoLund: Centre for Nanoscience
• Publishing year: 2017-05-31
• Language: English
• Pages: 1922-1929
• Publication/Series: ACS Omega
• Volume: 2
• Issue: 5
• Links: http://dx.doi.org/10.1021/acsomega.7b00316
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Physical Chemistry (including Surface- and Colloid Chemistry); Condensed Matter Physics (including Material Physics, Nano Physics)
• Status: Published
• ISBN/ISSN/Other: ISSN: 2470-1343