Synthesis And Modification Of Hybrid Cdse/Zns Quantum Dots

Abstract

The CdSe quantum dots (QD) synthesized by the colloidal method were stabilized with oleic acid (OA) and their optical properties were studied. The average size of the detected nanoparticles, depending on the peak of exciton absorption, was 3.7 nm. CdSe/ZnS hybrid core-shell quantum dot nanocrystals were synthesized by depositing a ZnS shell on the surface of CdSe nanoparticles. At the same time, the quantum yield of luminescence increased from 1.5 to 19%. As a result of the exchange of cadmium ions for zinc ions on the surface of the core of hybrid quantum dots, the size of the CdSe nucleus decreased to 2.8 nm. As a result, the absorption of the CdSe/ZnS hybrid quantum dot and the peak of the spectral wavelengths of luminescence moved to a short region. After growing the ZnS shell, a slight increase in the total hydrodynamic quantum dot particle size was observed. The effect of the nature of stabilizers on the synthesis of nanoparticles is studied. This process was carried out by surface alteration reactions. Molecules retained by the thiol group, which are strongly bound to the surface of nanocrystals, have been found to have effective exchange properties of dodecyl esters of dodecanthiol-1 and dihydrolipoic acid. It is proved by infrared (IR) spectroscopy that stabilizers were replaced. The optical-dimensional properties of stabilized quantum dots were studied.