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Updated: Jul 23, 2025

Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Synthesis, Structure, Morphology, Element composition, Electrochemical, and Optical studies of Zn0.98-XMn0.02CeX
P Sakthivel1, R V Mangalaraja2, G Ramalingam3
1Centre for Materials Science, Department of Physics, Science and Humanities, Faculty of Engineering, Karpagam Academy of Higher Education, Coimbatore - 641 021, Tamil Nadu, India.
Abstract:
Quantum dots (QDs) are semiconductors whose size falls in a range between 1 and 10 nm; they are generally known as zero-dimension materials. It finds various applications in optical industries including light-emitting diodes, display technology, imaging, and labelling. ZnS is one of the excellent QDs in its class of II-VI semiconductors. In this paper, It is reported that the preparation of Mn-doped ZnS and Mn, Ce co-doped ZnS QDs using facile co-precipitation technique. XRD and HR-TEM results confirmed the cubic structure, particle size, and phase of the synthesized particles, and the crystallite is measured as ∼ 2 nm. The surface morphology, elemental analysis, and FT-IR spectra revealed the purity of the samples and confirmed the presence of dopants as expected. Cyclic voltammetry studies expressed the electrochemical behaviour of the samples, which increased as a function of Ce3+ doping concentration. UV-visible absorbance and transmittance spectra disclosed the optical characteristics of the samples. A wide band gap (4.02 eV) was received for 2% Ce-doped Zn: MnS QDs. Week Blue and strong yellow emissions were received for 4% Ce-doped Zn:MnS QDs. Whereas, high intensity red-emission was received for 2% Ce-doped Zn:MnS QDs. The different colour emissions are discussed in terms of defects produced.

