Synthesis and Characterization of Mn Doped ZnS Quantum Dots from a Single Source Precursor

1998 ◽  
Vol 536 ◽  
Author(s):  
M. Azad Malik ◽  
Paul O’Brien ◽  
N. Revaprasadu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Hexagonal Phase ◽  
Esr Spectra ◽  
Near Band Edge ◽  
Photoluminescence Intensity ◽  
Single Source ◽  
Transmission Electron ◽  
Mn Doped

AbstractNanoparticles of ZnS and Mn-doped ZnS capped with TOPO (tri-n-octylphosphine oxide) and close to mono-dispersed have been prepared by a single source route using bis(diethyldithiocarbamato) zinc(II) as a precursor. The nanoparticles obtained show quantum size effects in their optical spectra and ZnS nanoparticles exhibit near band-edge luminescence. Clear difference in photoluminescence results between ZnS and ZnS:Mn samples. Changes in Mn-doping levels are shown by the changes in photoluminescence intensity. The most intense photoluminescence was observed for 1% and the least intense for 5% doping level. ESR spectra and ICP results confirm the presence of Mn in ZnS quantum dots and also correspond to the amount of Mn in each ZnS:Mn sample.The Selected Area Electron Diffraction (SAED), X-ray diffraction (XRD) pattern and Transmission Electron Microscopy (TEM) show the material to be of the hexagonal phase. The crystallinity of the material was also evident from High Resolution Transmission Electron Microscopy (HRTEM) which gave well-defined images of nanosize particles with clear lattice fringes.

Hydrothermal Synthesis of Hexagonal Phase Zn1-XMnxS (x = 0–0.05) Nanorods Using Single-Source Precursors

2010 ◽  
Vol 663-665 ◽  
pp. 100-103
Author(s):  
Zhen Ni Du ◽  
Yong Cai Zhang ◽  
Zhi You Xu ◽  
Ming Zhang
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Transmission Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Diffuse Reflectance ◽  
Hexagonal Phase ◽  
Single Source ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

The synthesis of hexagonal phase Zn1-xMnxS (x = 0–0.05) nanorods was achieved by hydrothermal treatment of zinc manganese diethyldithiocarbamates (Zn1-xMnx-(DDTC)2, x=0–0.05) in 40 mass % hydrate hydrazine aqueous solution at 180 °C for 12 h. The structure, composition and optical property of the obtained products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy and UV-vis diffuse reflectance spectra.

Synthesis and Characterization of Mn Doped CdS Quantum Dots from a Single Source Precursor

1999 ◽  
Vol 581 ◽  
Author(s):  
M. Azad Malik ◽  
Paul O'Brien ◽  
N. Revaprasadu
Keyword(s):  
Hexagonal Phase ◽  
Tetrahedral Site ◽  
Deep Trap ◽  
Esr Spectra ◽  
Cds Nanoparticles ◽  
Near Band Edge ◽  
Single Source ◽  
High Resolution Tem ◽  
Pl Spectrum ◽  
Mn Doped

ABSTRACTCdS and Mn-doped CdS capped with TOPO (tri-n-octylphosphineoxide) have been prepared by a single source route using bis(methylhexyldithiocarbamato)cadmium(II) and manganese dichloride as precursors. The nanoparticles obtained show quantum size effects in their optical spectra with the CdS nanoparticles exhibiting near band-edge luminescence. The PL spectrum of the doped CdS nanoparticles have an emission maximum at 585 nm attributed to the 4T1-6A1 electronic transition of Mn in a tetrahedral site. However the PL spectrum changes over time (weeks) and gave a deep trap emission. The Selected Area Electron Diffraction (SAED) and X-ray diffraction (XRD) pattern show both CdS and the Mn doped CdS particles to be of the hexagonal phase. Transmission Electron Microscopy (TEM) and High Resolution TEM show well-defined images of nanosize particles with clear lattice fringes. ESR spectra and ICP results confirm the presence of Mn in the CdS nanoparticles.

Solvothermal Synthesis of Mn-Doped CdS Nanorods Using Single-Source Molecular Precursors

2011 ◽  
Vol 284-286 ◽  
pp. 667-670
Author(s):  
Zhen Ni Du ◽  
Zhi You Xu ◽  
Yong Cai Zhang ◽  
Ming Zhang
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Hexagonal Phase ◽  
Single Source ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molecular Precursors ◽  
Cds Nanorods ◽  
Transmission Electron ◽  
Mn Doped

The synthesis of hexagonal phase Mn-doped CdS (Cd1-xMnxS) nanorods was achieved by solvothermal treatment of a class of easily obtained, air-stable single-source molecular precursors (cadmium manganese diethyldithiocarbamates, Cd1-xMnx-(DDTC)2) in ethylenediamine at 180 °C for 12 h. The structures and compositions of the as-synthesized products were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy and transmission electron microscopy.

Application of Tem on Sub-Half Micron Semiconductor Devices

1998 ◽  
Vol 523 ◽  
Author(s):  
Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Failure Analysis ◽  
Process Evaluation ◽  
Semiconductor Devices ◽  
Single Source ◽  
Process Step ◽  
Transmission Electron ◽  
Single Process ◽  
Single Process Step

AbstractApplication of transmission electron microscopy on sub-half micron devices has been illustrated in terms of process evaluation and failure analysis. For process evaluation, it is emphasized that a large number of features need to be examined in order to have reliable conclusions about the processes, while for failure analysis, the goal is to pin-point a single process step causing failure or a single source introducing the particle defect.

AQUEOUS SYNTHESIS OF HIGH QUANTUM YIELD AND MONODISPERSED THIOL-CAPPED CdxZn1-xTe QUANTUM DOTS BASED ON ELECTROCHEMICAL METHOD

NANO ◽  
2012 ◽  
Vol 07 (02) ◽  
pp. 1250011 ◽  
Author(s):  
JUNWEI LI ◽  
YANG JIANG ◽  
YUGANG ZHANG ◽  
DI WU ◽  
ANQI LUO ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Quantum Yield ◽  
Electrochemical Method ◽  
Large Scale ◽  
Ostwald Ripening ◽  
Visible Absorption ◽  
Aqueous Synthesis ◽  
Transmission Electron

A facile green approach has been developed to control the growth regime in the aqueous synthesis of CdxZn1-xTe semiconductor quantum dots (QDs) based on the electrochemistry method. The Low growth temperature and slow injection of Te precursor are used to prolong the diffusion controlled stage and thus suppress Ostwald ripening during the nanocrystal growth. The experimental results showed that a low concentration of Te precursor will definitely influence the growth procedure. The UV–visible absorption spectra, as well as transmission electron microscopy (TEM) shows the QDs a good monodispersity at any interval of the reaction procedure. The high-resolution transmission electron microscopy (HRTEM) images and powder X-ray diffraction (XRD) pattern suggested that the as-prepared QDs have high crystallinity and cubic structure. The size and composition-dependent fluorescent emission wavelength of the resultant CdxZn1-xTe alloyed QDs can be tuned from 460 to 610 nm, and their photoluminescent quantum yield can reach up to 70%. Especially in the wavelength range of 510–578 nm, the overall PL QYs of the as-prepared CdxZn1-xTe QDs were above 50%. The current work suggests that electrochemical method is an attractive approach to the synthesis of high-quality II-VI ternary alloyed semiconductor QDs at large-scale with a prominent cost advantage.

Optical properties and energy transfer processes in Tb3+-doped ZnSe quantum dots

2021 ◽  
Author(s):  
Nguyen Ca ◽  
N. D Vinh ◽  
Phan Van Do ◽  
N. T. Hien ◽  
Xuan Hoa Vu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Chemical Method ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Transfer Processes ◽  
Transmission Electron ◽  
Wet Chemical

Tb3+-doped ZnSe quantum dots (QDs) with Tb content in the range of 0.5 - 7% were successfully synthesized by a wet chemical method. X-ray diffraction (XRD) and transmission electron microscopy...

Microstructure characteristics of non-monodisperse quantum dots: on the potential of transmission electron microscopy combined with X-ray diffraction

CrystEngComm ◽  
2020 ◽  
Vol 22 (21) ◽  
pp. 3644-3655
Author(s):  
Stefan Neumann ◽  
Christina Menter ◽  
Ahmed Salaheldin Mahmoud ◽  
Doris Segets ◽  
David Rafaja
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Dots ◽  
Cdse Quantum Dots ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Characteristics ◽  
Scale Bridging ◽  
Transmission Electron ◽  
Hot Injection

Capability of TEM and XRD to reveal scale-bridging information about the microstructure of non-monodisperse quantum dots is illustrated on the CdSe quantum dots synthesized using an automated hot-injection method.

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