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Experimental and theoretical investigations of 4-hydroxy L-proline cadmium chloride nonlinear optical crystal
摘要： The solution grown structure 4-hydroxy L-proline cadmium chloride (4HLPCC) single crystal has been done by means of X-ray diffraction method. The computational quantum mechanical modelling method was performed with B3LYP level and LanL2DZ basis set to determine optimized geometry, dipolar moment, linear polarizability, first order hyperpolarizability, atomic charges of various atoms, thermodynamic parameters, HOMO-LUMO energy gap and vibrational frequencies of 4HLPCC. The vibrational frequencies of 4HLPCC were observed experimentally through FTIR and FT-RAMAN analyses and compared with theoretical frequencies. The electric properties were detected by dielectric studies. The frequency doubling of the grown crystal was made with Kurtz-Perry powder technique.
关键词： Polarizability,4-hydroxy L-proline cadmium chloride,DFT,Nonlinear optical properties,Hyperpolarizability
更新于2025-09-23 15:19:57
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Studying the Effect of Deposition Time on Optical Properties of CdS Thin Films
摘要： We have studied in this work the effect of deposition time on the absorption spectra and the optical energy gap of CdS thin film. That prepared by chemical bath deposition method (CBD) on glass substrate at temperature of (80 ± 5)°C. The structural features were examined by X-ray diffraction (XRD) is wurtzite structure for all samples. Transmittance spectra have been recorded in order to determine absorbance, reflectivity, absorption coefficient and the optical constants such as refractive index, extinction coefficient, real and imaginary part of dielectric constant. It was seen that all the parameters under investigation affected by deposition time (1,2 3, and 4) hours.
关键词： Cadmium sulfide,optical constants,chemical bath technique
更新于2025-09-19 17:15:36
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Nonlinear Optical Properties of CdS Semiconductor nanowires
摘要： In this work, we report on the nonlinear optical properties in single Cadmium sulfide nanowires (CdS NWs). The high qulity growth of CdS semiconductor nanowires were synthesized by chemical vapor deposition (CVD) method. The as-obtained products were characterized by X-ray diffraction (XRD) , Scanning electron microscopy (SEM), and the energy dispersive X-ray spectrom (EDS) was used to determine the specific elemental distribution and show purity of the CdS semiconductor nanowires . The excitation of femtosecond laser(800 nm, 50 fs, 80 MHz) was used to study the nonlinear optical properties of CdS nanowires, such as the Second Harmonic Generation(SHG) and optical waveguide effect. CdS NW has a second harmonic generation with a blue emission bands at a wavelength of 400 nm . Finally, based on the dark field image of the CCD taken and combined with the spectrum, it is proved that CdS NW has an optical waveguide effect.
关键词： Cadmium sulfide (CdS),Waveguide,nanowires (NWs),Second- Harmonic Generation (SHG),Chemical Vapor Deposition (CVD)
更新于2025-09-19 17:15:36
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Robust Polymer Matrix Based on Isobutylene (Co)Polymers for Efficient Encapsulation of Colloidal Semiconductor Nanocrystals
摘要： We introduce new oxygen- and moisture-proof polymer matrices based on polyisobutylene (PIB) and its block copolymer with styrene (poly(styrene-block-isobutylene-block-styrene), PSt-b-PIB-b-PSt) for encapsulation of colloidal semiconductor nanocrystals. In order to prepare transparent and processable composites, we developed a special procedure of the nanocrystal surface engineering including ligand exchange of parental organic ligands to inorganic species followed by attachment of specially designed short-chain PIB functionalized with amino-group (PIB-NH2). The latter provides excellent compatibility of the particles with the polymer matrices. As colloidal nanocrystals, we chose CdSe nanoplatelets (NPLs), since they possess a large surface and thus are very sensitive to the environment, in particular in terms of their limited photostability. The encapsulation strategy is quite general and can be applied to a wide variety of semiconductor nanocrystals, as demonstrated on the example of PbS quantum dots. All obtained composites exhibited excellent photostability being tested in a focus of a powerful white-light source, as well as exceptional chemical stability in a strongly acidic media. We compared these properties of the new composites with those of widely used polyacrylate based materials, demonstrating the superiority of the former. The developed composites are of particular interest for application in optoelectronic devices, such as color-conversion light emitting diodes (LEDs), laser diodes, luminescent solar concentrators, etc.
关键词： photoluminescence,nanocrystals-in-polymer composites,lead sulfide quantum dots,semiconductor nanocrystals,isobutylene (co)polymers,cadmium selenide nanoplatelets,photostability,chemical stability
更新于2025-09-19 17:15:36
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AVALIA??O DO PAPEL DO óXIDO DE GRAFENO (GO) NA GERA??O FOTOCATALíTICA DE HIDROGêNIO EM SISTEMAS BINáRIOS (GO-CdS) E TERNáRIOS (Pt-GO-CdS)
摘要： EVALUATION OF THE GRAPHENE OXIDE (GO) ROLE IN THE PHOTOCATALYTIC GENERATION OF HYDROGEN IN BINARY (GO-CdS) AND TERNARY (Pt-GO-CdS) SYSTEMS. Water splitting is a promising process to produce hydrogen from friendly feedstock and solar energy. In this work we have evaluated binary (GO-CdS) and ternary (Pt-GO-CdS) hybrid photocatalysts for hydrogen production assisted by visible light irradiation. Cadmium sulfide and composites with GO were prepared by sonochemical and thermal methods. GO addition took place by different strategies: during the synthesis or by mechanical mixture. A variety of configurations was tested and the best performance in hydrogen production among all materials was the ternary photocatalyst named Pt(GO/CdSTT), whose hydrogen production rate was 651 μmol gcat-1 h-1. Such material was obtained by thermal method with GO addition during the synthesis. Additionally, the XRD and Raman analyses have confirmed the GO photoreduction during photocatalytic hydrogen evolution.
关键词： graphene,water splitting,cadmium sulfide,visible light,hydrogen,photocatalysis
更新于2025-09-19 17:15:36
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Variety-dependent responses of rice plants with differential cadmium accumulating capacity to cadmium telluride quantum dots (CdTe QDs): Cadmium uptake, antioxidative enzyme activity, and gene expression
摘要： The excess release of engineered nanomaterials into farmland poses a serious threat to food security. Although rice varieties exhibit substantial variation in cadmium accumulation, their responses to Cd-based nanoparticles are largely unknown. In this work, we investigated the accumulation of cadmium telluride quantum dots (CdTe QDs at 0.5, 1.0, 2.5, 5.0 mg-Cd/L) in two rice varieties with different Cd accumulation capacity. It was found that 5.0 mg-Cd/L of CdTe QDs had minor growth inhibition to the high-Cd-accumulating variety (T705) relative to the low-Cd-accumulating variety (X24) after 7-day exposure. The two rice varieties had comparable Cd content in roots; however, T705 exhibited higher Cd content in shoots than X24. Transmission electron and confocal laser scanning microscopic observations demonstrated that more CdTe QDs can be transported and accumulated from roots to shoots in T705. The activities and gene expression of antioxidative enzymes in leaves of T705 increased more significantly than those of X24. Our findings for the first time validated that Cd accumulation divergence exists in different rice varieties when they are exposed to Cd-based QDs, the genetic basis for which needs to be further examined.
关键词： Gene expression,Antioxidant enzyme activity,Cadmium accumulation,Rice variety,Cadmium telluride quantum dots
更新于2025-09-19 17:13:59
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Enhancement of open circuit voltage of CdTe solar cell
摘要： In the present work, FTO/CdS/CdTe/Te/Al superstrate structured solar cell has been fabricated using thermal evaporation method. A 40 nm thin layer of P-type tellurium has been incorporated between CdTe and back contact to reduce the potential energy barrier by improving the quality of interfaces. The fabricated device characterized using UV–Visible-NIR spectroscopy and I–V measurement. The tellurium interlayer plays a vital role in enhancing the performance of the device. The fabricated device generated open circuit voltage (Voc) of 0.7 V.
关键词： Open-circuit voltage (Voc),I–V characteristics,Thermal evaporator,Solar cell,Cadmium Telluride (CdTe),UV–Visible-NIR spectroscopy
更新于2025-09-19 17:13:59
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Preparation of Highly Stable and Photoluminescent Cadmiuma??Free InP/GaP/ZnS Core/Shell Quantum Dots and Application to Quantitative Immunoassay
摘要： Indium phosphide (InP) quantum dots (QDs) are ideal substitutes for widely used cadmium-based QDs and have great application prospects in biological fields due to their environmentally benign properties and human safety. However, the synthesis of InP core/shell QDs with biocompatibility, high quantum yield (QY), uniform particle size, and high stability is still a challenging subject. Herein, high quality (QY up to 72%) thick shell InP/GaP/ZnS core/shell QDs (12.8 ± 1.4 nm) are synthesized using multiple injections of shell precursor and extension of shell growth time, with GaP serving as the intermediate layer and 1-octanethiol acting as the new S source. The thick shell InP/GaP/ZnS core/shell QDs still keep high QY and photostability after transfer into water. InP/GaP/ZnS core/shell QDs as fluorescence labels to establish QD-based fluorescence-linked immunosorbent assay (QD-FLISA) for quantitative detection of C-reactive protein (CRP), and a calibration curve is established between fluorescence intensity and CRP concentrations (range: 1–800 ng mL?1, correlation coefficient: R2 = 0.9992). The limit of detection is 2.9 ng mL?1, which increases twofold compared to previously reported cadmium-free QD-based immunoassays. Thus, InP/GaP/ZnS core/shell QDs as a great promise fluorescence labeling material, provide a new route for cadmium-free sensitive and specific immunoassays in biomedical fields.
关键词： cadmium-free,quantum dot-based fluorescence-linked immunosorbent assays,thick shell InP core/shell quantum dots,C-reactive proteins,quantitative detection
更新于2025-09-19 17:13:59
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Inert gas cluster formation in sputter-deposited thin film CdTe solar cells
摘要： Magnetron sputtering is widely used for thin film deposition because it is a relatively low temperature process which also produces films with excellent uniformity. Unfortunately, in its use for the deposition of thin film CdTe devices, the inert working gas from the magnetron can incorporate into the film during the growth process and aggregate into large subsurface clusters during postprocessing. The gas clusters often occur at the CdS/CdTe interface causing delamination and blisters up to about 30 μm in diameter are readily observable on the film’s surface. The surface blisters are observed after postprocessing with CdCl2 at an elevated temperature but smaller inert gas clusters of several nanometres in diameter can be observed using high resolution transmission electron microscopy before the CdCl2 treatment. In this paper, these effects are investigated both experimentally and using molecular dynamics modelling. Some suggestions are also made as to how the effect might be minimised and higher efficiency solar devices fabricated.
关键词： Solar Cells,Cadmium Telluride,Argon bubbles,Molecular Dynamics,High Resolution Electron Microscopy,Magnetron Sputtering
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Study of Se and Cl segregation in poly-crystalline CdSeTe
摘要： CdTe based thin film solar cells have shown to be competitive in terms of efficiency and low cost, but the polycrystalline structure and low minority carrier lifetime constrain CdTe based devices from reaching the theoretical efficiency limit. In this work, the effect of Se and Cl segregation in polycrystalline CdSeTe photovoltaic devices was studied. We demonstrated using two-photon time-resolved photoluminescence (TRPL) that the Se alloyed CdSeTe absorber layer shows high minority carrier lifetime, and used density functional theory (DFT) calculations to explain the origin of such high lifetime.
关键词： photovoltaic cells,II-VI semiconductor materials,cadmium compounds,selenium
更新于2025-09-19 17:13:59