Fabrication of Low Cost 1D CdSe Nanowires using Near-field Electrospinning

2011 ◽  
Vol 1302 ◽  
Author(s):  
Leroy Magwood ◽  
Binil Starly
Keyword(s):  
Quantum Dots ◽  
Fluorescence Microscopy ◽  
Fiber Diameter ◽  
Low Cost ◽  
Near Field ◽  
Light Attenuation ◽  
Dimethyl Formamide ◽  
Cdse Quantum Dot ◽  
The Matrix ◽  
Cdse Nanowires

ABSTRACTWell-aligned, 1D CdSe quantum dot (QD) fibers (0.3μm to 2.5μm) containing up to 20wt% fluorescent quantum dots (QDs) were prepared by near-field electrospinning (NFES) process. Electrospun solutions were prepared using PVAc as the matrix polymer, dimethyl formamide (DMF) solvent and colloidal QDs in chloroform (CHCl3). The diameter of the fibers decreased as the ratio of DMF/CHCl3 is varied. QDs showed good dispersion and a linear relationship between QD loading and fiber diameter, as determined by the morphology measurements taken using TEM and SEM, respectively. Fluorescence microscopy shows that there is light attenuation throughout the fibers. Results also show that the NFES process may be used as a method to create aligned, 1D fibers of QDs and potentially other nanofibers.

scholarly journals Effect of CdS/Mg-Doped CdSe Cosensitized Photoanode on Quantum Dot Solar Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Yingxiang Guan ◽  
Xiaoping Zou ◽  
Sheng He
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
High Performance ◽  
Low Cost ◽  
Energy Conversion Efficiency ◽  
Cdse Qds ◽  
Cdse Quantum Dot ◽  
Sensitized Solar Cells ◽  
Mg Doped

Quantum dots have emerged as a material platform for low-cost high-performance sensitized solar cells. And doping is an effective method to improve the performance of quantum dot sensitized solar cells (QDSSCs). Since Kwak et al. from South Korea proved the incorporation of Mg in the CdSe quantum dots (QDs) in 2007, the Mg-doped CdSe QDs have been thoroughly studied. Here we report a new attempt on CdS/Mg-doped CdSe quantum dot cosensitized solar cells (QDCSSC). We analyzed the performance of CdS/Mg-doped CdSe quantum dot cosensitized solar cells via discussing the different doping concentration of Mg and the different SILAR cycles of CdS. And we studied the mechanism of CdS/Mg-doped CdSe QDs in detail for the reason why the energy conversion efficiency had been promoted. It is a significant instruction on the development of Mg-doped CdSe quantum dot sensitized solar cells (QDSSCs).

scholarly journals Distance dependence of near-field fluorescence enhancement and quenching of single quantum dots

2011 ◽  
Vol 2 ◽  
pp. 645-652 ◽  
Author(s):  
Volker Walhorn ◽  
Jan Paskarbeit ◽  
Heinrich Gotthard Frey ◽  
Alexander Harder ◽  
Dario Anselmetti
Keyword(s):  
Quantum Dots ◽  
Fluorescence Microscopy ◽  
Single Molecule ◽  
Dipolar Coupling ◽  
Near Field ◽  
Fluorescence Emission ◽  
Field Enhancement ◽  
Single Quantum ◽  
Distance Dependence ◽  
Single Quantum Dots

In fluorescence microscopy and spectroscopy, energy transfer processes between single fluorophores and fluorophore quencher pairs play an important role in the investigation of molecular distances or orientations. At distances larger than about 3 nm these effects originate predominantly from dipolar coupling. As these experiments are commonly performed in homogenous media, effects at the interface boundaries can be neglected. Nevertheless, the combination of such assays with single-molecule manipulation techniques such as atomic force microscopy (AFM) requires a detailed understanding of the influence of interfaces on dipolar coupling effects. In the presented work we used a combined total internal reflection fluorescence microscopy (TIRFM)–AFM setup to elucidate this issue. We measured the fluorescence emission emanating from single quantum dots as a function of distance from the apex of a gold-coated cantilever tip. As well as fluorescence quenching at close proximity to the tip, we found a nonlinear and nonmonotonic distance dependence of the fluorescence emission. To confirm and interpret our findings we performed calculations on the basis of a simplified multiple multipole (MMP) approach, which successfully supports our experimental data. Moreover, we revealed and quantified the influence of interfering processes such as field enhancement confined at interface boundaries, mirror dipoles and (resonant) dipolar coupling.

Surface Passivation by Congeneric Quantum Dots for High-Performance and Stable CsPbBr3-Based Photodetectors

2021 ◽  
Author(s):  
Shikai Yan ◽  
Sheng Tang ◽  
Manman Luo ◽  
Lu Xue ◽  
Shilin Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
High Performance ◽  
Surface Passivation ◽  
Low Cost ◽  
Optoelectronic Properties ◽  
Solution Processing

CsPbBr3-based photodetectors (PDs) have aroused enormous attention owing to their low-cost solution processing, outstanding optoelectronic properties, and remarkable stability. However, their performances remain a big challenge to meet the requirement...

Anisotropic Nanostructure ZnO Photoelectrodes for CdS/CdSe Quantum Dot Sensitized Solar Cells

2013 ◽  
Vol 873 ◽  
pp. 556-561
Author(s):  
Jian Jun Tian
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Quantum Dot ◽  
Chemical Bath Deposition ◽  
Cdse Quantum Dots ◽  
Silar Method ◽  
Nanorods Array ◽  
Cdse Quantum Dot ◽  
Cbd Method ◽  
Sensitized Solar Cells

CdS/CdSe quantum dots co-sensitized solar cells (QDSCs) were prepared by combining the successive ion layer absorption and reaction (SILAR) method and chemical bath deposition (CBD) method for the fabrication of CdS and CdSe quantum dots, respectively. In this work, we designed anisotropic nanostructure ZnO photoelectrodes, such as nanorods/nanosheets and nanorods array, for CdS/CdSe quantum dots co-sensitized solar cells. Our study revealed that the performance of QDSCs could be improved by modifying surface of ZnO to increase the loading of quantum dots and reduce the charge recombination.

The direct observation of charge separation dynamics in CdSe quantum dots/cobaloxime hybrids

2016 ◽  
Vol 18 (6) ◽  
pp. 4300-4303 ◽  
Author(s):  
J. Huang ◽  
Y. Tang ◽  
K. L. Mulfort ◽  
X. Zhang
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Charge Separation ◽  
Cdse Quantum Dots ◽  
X Ray ◽  
Molecular Catalyst ◽  
Cdse Quantum Dot ◽  
Photoinduced Charge Separation ◽  
X Ray Absorption ◽  
Photoinduced Charge

In this work, we investigated photoinduced charge separation dynamics in a CdSe quantum dot/cobaloxime molecular catalyst hybrid using the combination of transient optical (OTA) and X-ray absorption (XTA) spectroscopy.

Advances in low-cost infrared imaging using II-VI colloidal quantum dots (Conference Presentation)

2017 ◽  
Author(s):  
Richard E. Pimpinella ◽  
Christopher Buurma ◽  
Anthony J. Ciani ◽  
Christoph H. Grein ◽  
Philippe Guyot-Sionnest
Keyword(s):  
Quantum Dots ◽  
Infrared Imaging ◽  
Low Cost ◽  
Colloidal Quantum Dots

Near-Field Magneto-Photoluminescence of Singe Self-Organized Quantum Dots.

2003 ◽  
Vol 794 ◽  
Author(s):  
A. M. Mintairov ◽  
A. S. Vlasov ◽  
J. L. Merz
Keyword(s):  
Quantum Dots ◽  
Near Field ◽  
Energy Shift ◽  
Zeeman Splitting ◽  
Negative Energy ◽  
Zero Magnetic Field ◽  
Bimodal Size Distribution ◽  
Self Organized ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

ABSTRACTWe present results obtained using low temperature near-field scanning optical microscopy for the measurements of Zeeman splitting and the diamagnetic shift of single self-organized InAs/AlAs, InAs/GaAs and InP/GaInP quantum dots. The measurements allow us to relate the bimodal size distribution of InAs dots with variations in In content. For single InP QDs we observed a strong circular polarization at zero magnetic field accompanied with a negative energy shift, suggesting that strong internal magnetic fields exist in these QDs.

FOAMING AND MOISTURE CROSSLINKING OF VINYL TRIETHOXY SILANE GRAFTED ETHYLENE–PROPYLENE–DIENE TERPOLYMER

2022 ◽  
Author(s):  
Zhengwei Lin ◽  
Qinghong Zhang ◽  
Gongliang Wang ◽  
Jie Mao ◽  
Martin Hoch ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Side Reaction ◽  
High Energy ◽  
Expansion Ratio ◽  
Ethylene Propylene ◽  
Foaming Process ◽  
The Matrix ◽  
High Energy Absorption ◽  
Ethylene Propylene Diene Terpolymer

ABSTRACT Moisture crosslinking of polyolefins has attracted increasing attention because of its high efficiency, low cost, and easy processing. However, the crucial shortcoming of moisture crosslinking is that the side reaction of peroxide scorch (precrosslinking) simultaneously occurs in silane grafting. It has been recognized that making peroxide precrosslinking useful is an effective way to broaden the application of moisture crosslinking. A novel foaming process combined with moisture crosslinking is proposed. The matrix of ethylene–propylene–diene terpolymer grafted with silane vinyl triethoxysilane (EPDM-g-VTES) was prepared by melt grafting, with dicumyl peroxide as initiator. Foaming was then carried out with azodicarbonamide (AC) as the blowing agent by making use of precrosslinking. Subsequently, the EPDM-g-VTES foams were immersed in a water bath to achieve moisture crosslinking with dibutyl tin dilaurate as the catalyst. The results showed that VTES was grafted onto EPDM and the EPDM-g-VTES foams were successfully crosslinked by moisture. The EPDM-g-VTES compounds with AC obtained great cells by compression molding with the help of precrosslinking. The mechanical property of the EPDM-g-VTES foam was improved by moisture crosslinking. The moisture-cured foam with 4 wt% AC had an expansion ratio of about three times, which could bear large deformation and showed a high energy-absorption effect.

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