Binary and Ternary Mercury Chalcogenide Quantum Dots and Clusters

2002 ◽  
Vol 737 ◽  
Author(s):  
Masaru Kuno ◽  
Keith A. Higginson ◽  
Syed B. Qadri ◽  
Mohammad Yousuf ◽  
Benjamin L. Davis ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Phase Separation ◽  
Near Infrared ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
High Quality ◽  
Synthetic Strategy ◽  
Simultaneous Use

ABSTRACTThis paper describes the synthesis, characterization and optical properties of binary and ternary mercury chalcogenide quantum dots and clusters. Such materials were made by applying a synthetic strategy involving the simultaneous use of strong Hg(II) coordinating ligands and the explicit phase separation of both metal and chalcogen precursors. High quality QDs and clusters are obtained in this manner with sharply structured absorption and band edge emission covering the visible to near infrared.

scholarly journals Fluorine-Doped Tin Oxide Colloidal Nanocrystals

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 863 ◽  
Author(s):  
Owen Kendall ◽  
Pierce Wainer ◽  
Steven Barrow ◽  
Joel van Embden ◽  
Enrico Della Gaspera
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Tin Oxide ◽  
Near Infrared ◽  
Transparent Electrode ◽  
High Quality ◽  
Detailed Characterization

Fluorine-doped tin oxide (FTO) is one of the most studied and established materials for transparent electrode applications. However, the syntheses for FTO nanocrystals are currently very limited, especially for stable and well-dispersed colloids. Here, we present the synthesis and detailed characterization of FTO nanocrystals using a colloidal heat-up reaction. High-quality SnO2 quantum dots are synthesized with a tuneable fluorine amount up to ~10% atomic, and their structural, morphological and optical properties are fully characterized. These colloids show composition-dependent optical properties, including the rise of a dopant-induced surface plasmon resonance in the near infrared.

Enhancement of Photoluminescence from Organic and Inorganic Surface Passivated ZnS Quantum Dots

2001 ◽  
Vol 667 ◽  
Author(s):  
Hatim Mohamed El-Khair ◽  
Ling Xu ◽  
Mingha Li ◽  
Yi Ma ◽  
Xinfan Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Organic Coating ◽  
Band Edge ◽  
Band Edge Emission ◽  
Trap States ◽  
Edge Enhancement ◽  
Edge Emission ◽  
Inorganic And Organic

ABSTRACTZnS quantum dots (QDs) chemically synthesized in PVP stabilizing medium have been coated with Zn(OH)2, SiO2and polystyrene (PS) shells as inorganic and organic passivation agents. to synthesize ZnS/Zn(OH)2, ZnS/SiO2and ZnS/PS QDs. PL properties of inorganically passivated ZnS/Zn(OH)2 and ZnS/SiO2 had reported band edge enhancement of 8-10 times, while organically passivated ZnS/PS QDs exhibit tremendous enhancement of band edge emission as much as 10-15 times,. Therefore inorganic and organic coating can passivate trap states of different energies on the surface of ZnS QDs.

Enhancement of Band Edge Emission from ZnS/Zn(OH) 2 Quantum Dots

2001 ◽  
Vol 18 (4) ◽  
pp. 616-618 ◽  
Author(s):  
Hatim Mohamed El-Khair ◽  
Xu Ling ◽  
Huang Xin-Fan ◽  
Li Ming-Hai ◽  
Chen Kun-Ji
Keyword(s):  
Quantum Dots ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission

Synthesis and optical characterization of a high-quality ZnS substrate for optoelectronics and UV solar-energy conversion

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 81053-81059 ◽  
Author(s):  
Ching-Hwa Ho ◽  
Min-Han Lin
Keyword(s):  
Solar Energy ◽  
Energy Conversion ◽  
Optical Characterization ◽  
Band Edge ◽  
Band Edge Emission ◽  
High Grade ◽  
Edge Emission ◽  
High Quality ◽  
Strong Band

A high-grade cubic ZnS substrate crystal with longer range order and a strong band-edge emission was clearly demonstrated.

Strong Band-Edge Emission from ZnS Quantum Dots Stabilized by Gum Arabic

2008 ◽  
Vol 25 (12) ◽  
pp. 4480-4481 ◽  
Author(s):  
Hatim Mohamed El-Khair Dirar
Keyword(s):  
Quantum Dots ◽  
Gum Arabic ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Strong Band

Formation and Optical Properties of ZnSe Self-Assembled Quantum Dots in Cl-Doped ZnSe Thin Films Grown on GaAs (100) Substrates

2007 ◽  
Vol 124-126 ◽  
pp. 567-570
Author(s):  
G.N. Panin ◽  
H.J. Kim ◽  
S.Y. Kim ◽  
J.H. Jung ◽  
Tae Whan Kim ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Confinement Effect ◽  
Blue Shift ◽  
Emission Peak ◽  
Band Edge ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Acceptor Pair ◽  
Small Quantum

The high-resolution scanning electron microscopy (HRSEM) image showed that selfassembled ZnSe small quantum dots (QDs) and large nanodots with a pyramid shape were formed in the Cl-doped ZnSe epilayers grown on GaAs (100) substrates. The formation of the ZnSe QDs was attributed to three-dimensional growth controlled by distribution of the impurities in the Cldoped ZnSe epilayrs. Cathodoluminescence (CL) measurements at room temperature revealed the emission peak at 3.1 eV corresponding to the blue shift approximately 400 meV from the near band edge emission of 2.7 eV in the bulk ZnSe. The blue shifted CL peak indicates the quantum confinement effect resulting from the formation of the ZnSe QDs in the Cl-doped ZnSe thin film. While the peak position of the donor-acceptor pair emission shifted to higher energies with decreasing temperature, the band-edge emission peak for the QDs did not significantly change.

Defect-rich ZnO quantum dots as a potential multifunctional sunscreen and cosmetic active ingredient

2015 ◽  
Vol 87 (9-10) ◽  
pp. 971-977 ◽  
Author(s):  
Adersh Asok ◽  
Ajit R. Kulkarni ◽  
Mayuri N. Gandhi
Keyword(s):  
Quantum Dots ◽  
Active Ingredient ◽  
Visible Region ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission ◽  
Zno Nps ◽  
Visible Luminescence ◽  
Zno Quantum Dots ◽  
Zno Qds

AbstractIn sunscreens, ZnO nanoparticles (NPs) are used as inorganic UV filter which have a prominent band edge emission in the UVA region (~385 nm). When applied to biological surface, this highly penetrating UVA emission from ZnO NPs would enhance the generation of reactive oxygen species resulting in oxidative stress. Therefore, the elimination of this harmful UVA emission from ZnO NPs are much sought after for the development of safer sunscreens. In this paper we introduce the use of defect-rich ZnO (D-ZnO) quantum dots (QDs) as a multifunctional active ingredient in sunscreen/cosmetic application. These D-ZnO QDs make use of their defect energy levels to emit in visible region by bypassing their harmful band edge emission at UVA region. The D-ZnO QDs also showed prominent visible luminescence which matches well with the autofluorescence of in vivo human skin. Hence, this visible luminescence could be useful for camouflaging, thereby enabling its potential as a biologically safe active ingredient for both cosmetic and UV screening applications.

High-Quality InGaAsP Crystals Grown by MOVPE Using TBA and TBP

1990 ◽  
Vol 216 ◽  
Author(s):  
A. Kuramata ◽  
S. Yasmazaki ◽  
K. Nakajima
Keyword(s):  
Optical Properties ◽  
Growth Conditions ◽  
Band Edge Emission ◽  
Photoluminescence Spectra ◽  
Edge Emission ◽  
High Quality ◽  
Electrical And Optical Properties ◽  
Group V ◽  
Movpe Growth ◽  
The Relationship

ABSTRACTTBA and TBP are attractive candidates for group V sources for MOVPE growth from the viewpoint of safety. We studied how the composition of InGaAsP crystals depends on growth conditions, and investigated its electrical and optical properties. The relationship between group V sources and crystals indicates that TBA and TBP decompose into AsH and PH. Since there is no carbon in AsH and PH, carbon contamination in the crystals is expected to be small. Carrier concentrations ranged from 5×1014 cm−3 to 1.5×1015 cm−3. Photoluminescence spectra at 4.2K showed strong band-edge emission with no acceptor-related emission. Based on the electrical and optical properties of the crystals, we conclude that high-quality InGaAsP crystals can be grown using TBA and TBP.

scholarly journals Enhancement of band-edge emission induced by defect transition in the composite of ZnO nanorods and CdSe/ZnS quantum dots

2008 ◽  
Vol 33 (6) ◽  
pp. 569 ◽  
Author(s):  
Lin-Jie Tzeng ◽  
Chung-Liang Cheng ◽  
Yang-Fang Chen
Keyword(s):  
Quantum Dots ◽  
Zno Nanorods ◽  
Band Edge ◽  
Band Edge Emission ◽  
Edge Emission
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