Journal Article

Synthesis and characterization of optic properties of CdSe and CdSe/ZnS quantum dots

Brayan Stiven Gómez Piñeros, Gilma Granados Oliveros

2018

Overview

CdSe and CdSe/ZnS (core/shell) quantum dots with oleic acid as stabilizing agent in organic medium were prepared and their optical properties were examined. For CdSe synthesis, the influence of O2 in the growth kinetics of quantum dots was determined. In the first 90 s, the nanocrystals growth was 1.6 higher in presence of O2 than when reaction was carried out in N2 atmosphere. However, the growth rate with O2 is not favorable because the nanocrystal optical properties were affected: wider absorption band and lower fluorescence that those obtained in inert atmosphere. Properties of CdSe nanocrystals synthesized in inert atmosphere were intensified with 10% of monolayer. For a core with 2.5 nm diameter, the fluorescence quantum yield (ΦFl) in the green region increased from 5.5% to 42.3%. In this work, a low Zn2+ (diethylzinc) precursor concentration was used to produce a. The synthesis process of CdSe / ZnS nanocrystals developed with low concentration of Zn2+ and an excess of S2- can be used to obtain materials with excellent photoluminescent properties for applications such as biomarkers, sensors, catalysis, and solar cells.

• Publisher: Universidad Nacional de Colombia
• Subject: absorción / Excitón / fluorescencia / puntos cuánticos / rendimiento cuántico