Abstract
CdTe and CdTe/CdS quantum dots (QDs) were prepared in aqueous solutions using thioglycolic acid as a stabilizing agent. The photoluminescence (PL) wavelength of the QDs depended strongly on the size of CdTe cores and the thickness of CdS shells. Being kept at room temperature for 130 days, the PL wavelength of CdTe and CdTe/CdS QDs was red-shifted. However the red-shifted degree of CdTe QDs is larger than that of CdTe/CdS QDs. The size of CdTe QDs and the thickness of CdS play important roles for the red-shift of PL spectra of CdTe/CdS QDs. In contrast, the full width at half maximum of PL spectra of CdTe and CdTe/CdS QDs almost remained unchanged. This is ascribed to the effects of Cd2+ and TGA in solutions on the growth of CdTe and CdTe/CdS QDs. This associated with the variation of surface state of the QDs during store. The results demonstrate that CdTe/CdS core/shell QDs have high stability compared with CdTe QDs due to a CdS shell.
Highlights
Quantum dots (QDs) have attracted considerable interest in the past two decades because of their excellent properties such as narrower and symmetric emission spectra, broad absorption spectra, and better photostability than traditional fluorescent labels [1,2,3,4,5]
thioglycolic acid (TGA)-capped CdTe/CdS core/shell QDs in an aqueous solution were synthesized by depositing a CdS shell on CdTe cores in an aqueous solution
The epitaxial growth of the CdS shell was confirmed by the red-shifted absorption and emission spectra of the CdTe/CdS core/shell QDs and the X-ray diffraction (XRD) patterns of the QDs
Summary
Quantum dots (QDs) have attracted considerable interest in the past two decades because of their excellent properties such as narrower and symmetric emission spectra, broad absorption spectra, and better photostability than traditional fluorescent labels [1,2,3,4,5]. An organic synthetic approach in trioctylphosphine or trioctylphosphine oxide at high temperature has been well developed to prepare highly luminescent II–VI QDs [6]. The QDs are insoluble in an aqueous solution and not compatible for biological applications. An alternative approach to produce water soluble QDs is to directly synthesize QDs in an aqueous solvent. Such approach is less expensive, highly reproducible, less toxic, and more biocompatible [7]. It is easy to control QD size in an aqueous approach because of a low nucleation and growth rate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
