Cadmium sulfide

In this work, we present the synthesis and characterization of CdS nanoparticles suitable for semiconductor applications using a simple and manufacturable process. The solution based process was synthetized at room temperature using cadmium nitrate tetrahydrate (Cd (NO 3 ) 2 .4 H 2 O 0.1 M) and a Thioacetamide (C 2 H 5 NS (TA) 0.5 M) as source of cadmium and sulfur, respectively. The effect of the concentration of polyethyleneimine (PEI) as a surface stabilizer or surfactant for growth control of CdS nanoparticles was studied. The PEI concentrations were varied as 1 M, 0.5 M , 0.25 M , and 0.01 M respectively. Optical properties of CdS were analyzed by UV-Vis spectroscopy; functional groups were identified by Fourier transform infrared spectroscopy (FTIR) and the surface morphology by scanning electron microscopy (SEM). The particle size for CdS nanoparticles were less than 80 nm. An increase in size was observed inversely to the PEI concentration.

Cadmium sulfide (CdS) and cadmium telluride (CdTe) are two leading semiconductor materials used in the fabrication of thin film solar cells of relatively high power conversion efficiency and low manufacturing cost. Numerical simulations of current-voltage characteristics of thin film CdS/CdTe solar cell and nanowire CdS/CdTe solar cell were performed as a function of temperature using SCAPS-1D to demonstrate the fact that use of CdS nanowires enhances the efficiency of the CdS/CdTe solar cells. For the simulation of nanowire CdS/CdTe solar cell we changed some parameters (thickness, bandgap, electron and hole mobility) of the simulation of thin film CdS/CdTe solar cell. The Optical properties (absorption and scattering cross section) of CdS nanowire were observed to determine the preferable diameter for CdS nanowires. Simulations for realizing the absorption and scattering cross sections for various diameters of CdS nanowire were done using Lumerical FDTD solutions. From simulation results it was evident that nanowire CdS design was superior to planar CdS film due to enhanced performance in the CdS/CdTe solar cell through higher open circuit voltage and higher efficiency as for thin film CdS/CdTe solar cell the open circuit voltage was 0.6908V and efficiency was 14.15%. For nanowire CdS/CdTe solar cell model the open circuit voltage was 0.7889V and efficiency was 15.07%. Device parameters such as: thickness, bandgap, interface state density, density of states, electron and hole mobility, trap density, metal work function, temperature, parasitic series and shunt resistance were studied which can affect the efficiency of the nanowire-CdS/CdTe solar cell. The rollover effect on nanowire CdS/CdTe solar cell was explained by varying the majority carrier barrier height of back contact from 0.4 to 0.7 eV. It proves that change of barrier height at the contact can cause rollover effect. The crossover effect was observed by varying the thickness of CdS nanowire layer and removing defect of i-SnO2 layer. It was evident that the removal of defect in i-SnO2 is responsible for producing the crossover effect. Though SCAPS-1D is basically designed for simulation of thin film solar cells, it can be concluded that SCAPS-1D can also provide realistic simulation for nanowire CdS/CdTe solar cells.

Recent progress with indium (III) sulfide (In2S3)-buffered thin film solar cells (TFSC) was briefly reviewed. In2S3 has emerged as a promising low-hazard buffer (or window) material, and has proven to improve the properties of the solar cells, while reducing toxicity. Various deposition techniques have been employed to synthesize In2S3 films on different types of substrates.  Until now, atomic layer deposition (ALD) and ionic layer gas atomic reaction (ILGAR) techniques have been the two most successful, yielding maximum energy conversion efficiencies up to 16.4% and 16.1%, respectively. The impact of varied deposition parameters upon the In2S3 film properties and performance of cadmium (Cd)-free solar cells has been outlined. A comparative/operational analysis (solar cell efficiencies above 9% reported for cell area ≤ 1cm2) of various buffer layers used in two primary types of TFSC technology: chalcopyrite (CIS/CIGS)- and CdTe-based solar cells was also performed to measure the progress of In2S3 compared to its counterparts.

Biological approaches have been amongst the most promising protocols for synthesis of nanomaterials.
In this study, Cadmium sulfide nanoparticles (CdS NPs) were synthesized by incubating their precursor
salts with Escherichia coli and zeta potential (z-potential) measurement with varying pH was carried out
to evaluate stability of the colloidal dispersion. Formation of CdS NPs was studied in synchrony with
microbial growth. TEM analysis confirmed the uniform distribution of NPs. Average size (5 ± 0.4 nm) and
electron diffraction pattern revealed polycrystalline cubic crystal phase of these nanoparticles. X-ray
diffractogram ascertained the formation of CdS nanoparticles with phase formation and particle size
distribution in accordance with the particle size obtained from TEM. Absorption edge of biosynthesized
CdS NPs showed a blue shift at ~400 nm in comparison to their bulk counterpart. A hump at 279 nm
indicated presence of biomolecules in the solution in addition to the particles. FT-IR spectrum of capped
CdS NPs showed peaks of protein. This confirms adsorption of protein molecules on nanoparticle surface.
They act as a capping agent hence responsible for the stability of NPs. The enhanced stability of the
particles was confirmed by Zeta potential analysis. The presence of charge on the surface of capped CdS
NPs gave a detail understanding of dispersion mechanism and colloidal stability at the NP interface. This
stability study of biosynthesized semiconductor nanoparticles utilizing microbial cells had not been done in the past by any research group providing an impetus for the same. Surface area of capped CdS NPs and bare CdS NPs were found to be 298 ± 2.65 m2/g and 117 ± 2.41 m2/g respectively. A possible mechanism is also proposed for the biosynthesis of CdS NPs.

Nanorod arrays of zinc oxide–zinc stannate core–shell photoelectrodes were prepared by a simple hydrothermal process and cadmium sulfide (CdS) quantum dot sensitized solar cells were fabricated. The photocurrent density of the core–shell photoelectrode was found to improve by ∼2.4 times compared to ZnO nanorod photoelectrodes, due to improved surface area and charge transport in the core–shell photoelectrodes. With a thin layer of ZnS on the CdS quantum dot surface, the core–shell quantum dot sensitized solar cell demonstrated maximum power conversion efficiency of 1.24% under 1 sun illumination (AM1.5).

We present a potential solution to the problem of extraction of photogenerated holes from CdS nanocrystals and nanowires. The nanosheet form of C 3 N 5 is a low-band-gap (E g = 2.03 eV), azo-linked graphenic carbon nitride framework formed by the polymerization of melem hydrazine (MHP). C 3 N 5 nanosheets were either wrapped around CdS nanorods (NRs) following the synthesis of pristine chalcogenide or intercalated among them by an in situ synthesis protocol to form two kinds of heterostructures, CdS-MHP and CdS-MHPINS, respectively. CdS-MHP improved the photocatalytic degradation rate of 4-nitrophenol by nearly an order of magnitude in comparison to bare CdS NRs. CdS-MHP also enhanced the sunlight-driven photocatalytic activity of bare CdS NWs for the decolorization of rhodamine B (RhB) by a remarkable 300% through the improved extraction and utilization of photogenerated holes due to surface passivation. More interestingly, CdS-MHP provided reaction pathway control over RhB degradation. In the absence of scavengers, CdS-MHP degraded RhB through the N-deethylation pathway. When either hole scavenger or electron scavenger was added to the RhB solution, the photocatalytic activity of CdS-MHP remained mostly unchanged, while the degradation mechanism shifted to the chromophore cleavage (cycloreversion) pathway. We investigated the optoelectronic properties of CdS-C 3 N 5 heterojunctions using density functional theory (DFT) simulations, finite difference time domain (FDTD) simulations, time-resolved terahertz spectroscopy (TRTS), and photoconductivity measurements. TRTS indicated high carrier mobilities >450 cm 2 V −1 s −1 and carrier relaxation times >60 ps for CdS-MHP, while CdS-MHPINS exhibited much lower mobilities <150 cm 2 V −1 s −1 and short carrier relaxation times <20 ps. Hysteresis in the photoconductive J−V characteristics of CdS NWs disappeared in CdS-MHP, confirming surface passivation. Dispersion-corrected DFT simulations indicated a delocalized HOMO and a LUMO localized on C 3 N 5 in CdS-MHP. C 3 N 5 , with its extended π-conjugation and low band gap, can function as a shuttle to extract carriers and excitons in nanostructured heterojunctions, and enhance performance in optoelectronic devices. Our results demonstrate how carrier dynamics in core−shell heterostructures can be manipulated to achieve control over the reaction mechanism in photocatalysis.

CdS thin films were deposited by vacuum thermal evaporation technique on Fluorine-doped Tin Oxide glass substrates at different substrate temperatures ranging from 50 to 250 • C. Post deposition heat-treated thin films were characterized for optical, structural, morphological and electrical properties to study the dependence substrate temperature. The optical bandgap was found in the range of 2.42-2.46 eV. Crystallite size, microstrain, phase distribution, and lattice parameters were calculated using x-ray diffractogram profile fit, Rietveld and Pawley refinement techniques. Best electrical properties of photoelectrochemical cells were observed for the films grown at a substrate temperature of 175 • C. CdS/CdTe full cells were fabricated using thermal evaporation technique and the highest efficiency of 3.76% and highest external quantum efficiency of 70% were observed for the CdS thin film grown at a substrate temperature of 175 • C and the variation was confirmed with SCAPS-1D simulation.

Single step hydrothermal synthesis of CdS/Oxide (Oxide = ZnO, Al2O3) was demonstrated and examines their photocatalytic activity in presence of graphene oxide (GO). CdS/Al2O3/GO and CdS/ZnO/GO both exhibits enhanced photocatalytic activity for hydrogen generation with apparent quantum yields (AQY) of 14% and 30% respectively. Moreover, CdS/Oxide/GO displayed efficient photodegradation of organic dye; ~90% for CdS/Al2O3/GO and ~99% for CdS/ZnO/GO within 60 min of time interval. Superior photocatalytic properties are attributed to the enhanced surface area and effective separation of photoinduced charge carriers due to the presence of graphene oxide. The present study highlights the potential application of graphene based materials in the field of energy conversion and environment remediation.

PPy-CdS nanocomposite and multilayer thin film was deposited on Al substrate using electrodeposition technique. The presence of CdS particle in the composite film was proved using XRD and Micro-Raman spectroscopy. The roughness of the composite film was very low and it to be 4.96 nm. The fractal self-similarity of the composite films was estimated as 1.06. The resistance of PPy film along the polymer chain (sheet resistance) was 92.2 Ω and the resistance across the polymer chain (volume resistance) was 9.7 KΩ. However, the value of sheet resistance was 19.3 KΩ and the volume resistance was 43.6 KΩ for PPy-CdS nanocomposites film. Polymers acted as a corrosion protection layer for CdS nanoparticles. The rise and decay time constant of PPy-CdS nanocomposites film were obtained as 150s and 200s respectively and PPy-CdS multilayer films with bridge configuration were 203 s and 480 s respectively.

CdS nanoparticles were grown using CdSO4 and Na2S2O3 as the precursors and thioglycerol (TG) as the capping agent. TG was shown to exhibit a catalytic role in the reaction and also acted as a capping agent. It was demonstrated that size growth is linearly related to the temperature of the
reaction, i.e. the sizes can be controllably adjusted by temperature. The
crystalline phase of the nanocrystals was also dependent on the temperature
of growth: higher temperature favours the cubic phase. The pH also plays an important role in nanoparticle growth, as lower pH leads to a higher release rate of sulfur species. At pH as high as 10, the growth rate remains slow even
at boiling temperature. This provides a way to controllably grow nanoparticles at high temperatures and/or control the nucleation growth processes.

Photoelectrochemical cell technology is one of the simplest technologies, which converts light energy directly into electricity. The synthesis of cadmium sulfide (CdS) nanocrystals (NCs) was performed by the facile hot injection method. The NCs were characterized by different techniques such as XRD, Raman, UV-Vis, FESEM, and XPS. The XRD and Raman patterns confirm the phase pure hexagonal CdS NCs. The band gap of NCs calculated from the UV-Visible spectrum is at 2.64 eV, indicating good absorption in the visible spectrum. XPS analysis confirmed the presence of individual elements in CdS NCs. The CdS thin-films having different thicknesses were prepared on FTO substrates using the spin coating technique. Photoelectrochemical (PEC) investigation of CdS NCs thin-films photoelectrodes was performed by varying its thickness. The increase in the thickness of thin-films increased photocurrent density.

Nanourchin-shaped narrow-band-gap semiconductor photocatalysts with high surface area combined with good crystallinity result in effective photocatalysis. In this work, the impregnating growth of 1D CdS nanowires onto Al 2 O 3 and ZnO templates as cores generates novel urchinlike morphology of CdS@oxide photocatalysts. The CdS@Al 2 O 3 and CdS@ZnO nanourchins explicitly show a major role in enhanced hydrogen generation with apparent quantum yields (AQY) of 11% and 15%, respectively. Mechanistically, the template-based CdS can influence the photocatalytic activity in two ways: (i) direct well-dispersed growth of CdS onto the oxide core, leading to a high surface area for enhanced light absorption, and (ii) charge transfer from the conduction band of highly crystalline CdS to that of the oxide, which facilitate efficient charge separation for hydrogen production. Following these two mechanisms, a simple, low-cost, and environmentally friendly hydrothermal strategy is employed to synthesize novel nanourchin-shaped CdS-based heteroarrays. This new morphology stimulates the surface area per unit volume of the photocatalyst and exhibits promising application for photocatalytic water splitting.

Abstract CdS thin films were deposited by vacuum thermal evaporation technique on Fluorine-doped Tin Oxide glass substrates at different substrate temperatures ranging from 50 to 250 °C. Post deposition heat-treated thin films were characterized for optical, structural, morphological and electrical properties to study the dependence substrate temperature. The optical bandgap was found in the range of 2.42–2.46 eV. Crystallite size, microstrain, phase distribution, and lattice parameters were calculated using x-ray diffractogram profile fit, Rietveld and Pawley refinement techniques. Best electrical properties of photoelectrochemical cells were observed for the films grown at a substrate temperature of 175 °C. CdS/CdTe full cells were fabricated using thermal evaporation technique and the highest efficiency of 3.76% and highest external quantum efficiency of 70% were observed for the CdS thin film grown at a substrate temperature of 175 °C and the variation was confirmed with SCAPS-1D simulation.

Full Article Figures & data References Citations Metrics Reprints & Permissions Get access ABSTRACT Effect of sonication time on the synthesis of the CdS nanoparticles within the matrix obtained through the covalent functionalization of multiwall carbon nanotube (MWCNT) with maleic anhydride (MA) – 1-octene copolymer was investigated. Cadmium chloride and thiourea were used as the raw materials. MWCNTs used for the matrix were synthesized by Catalytic Chemical Vapor Deposition using Fe-Co/Al2O3 as the catalyst. The obtained nanostructures were characterized by FTIR, XRD, Raman spectroscopy, TEM, SEM, TG and UV-Vis spectroscopy. Electrophysical properties of the polymer nanocomposites obtained using different periods of time for sonication were comparably investigated. The average CdS particle diameter was between 3.9–7.9 nm as confirmed independently by TEM and XRD. UV-Vis spectroscopy revealed that the obtained nanostructures are appropriate base materials for making optical devices.

It is reported the application of the voltammetry of microparticles (VMP), complemented with attenuated total reflec‑ tance Fourier transform infrared spectroscopy (ATR‑FTIR) and field emission scanning electron microscopy (FESEM) techniques, to monitor the deterioration of verdigris pictorial specimens under the action of different biological agents. This methodology would be of application for identifying the type of biological agent causing deterioration of paintings, which is an important problem affecting cultural heritage. The analysis of biodeterioration processes is complicated by the fact that the action of microorganisms can affect both pigment and binding media. The deterio‑ ration of pictorial specimens combining verdigris with egg and egg–linseed oil binders by Penicillium chrysogenum, Aspergillus niger, Acremonium chrysogenum, Trychoderma pseudokoningi and Mucor rouxii fungi and Bacillus amylolique-faciens, Arthrobacter oxydans and Streptomyces cellulofans bacteria were tested using sample‑modified graphite elec‑ trodes immersed into aqueous electrolytes. A model is presented to describe the involved electrochemistry resulting in specific voltammetric features for the electrochemical reduction of verdigris associated to the proteinaceous and lipidic fractions of the binders. The experimental results and model proposed have been discussed and compared with those previously obtained for cadmium yellow reconstructed paint film specimens.

The synthesis of semiconductor nanoparticles is a growing research area due to the prospective applications for the development of novel technologies. In this paper we have reported the biosynthesis of Cadmium sulfide nanoparticles (CdSNPs) by reduction of cadmium sulphate solution, using the bacteria of Serratia nematodiphila. The process for the synthesis of CdS nanoparticles is fast, novel and ecofriently. Formation of the CdS nanoparticles was confirmed by surface Plasmon spectra using UV-Vis spectrophotometer and absorbance strong peak at 420 nm. The morphology of crystalline phase of nanoparticles was determined from Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy and X-ray diffraction (XRD) spectra. The average size of CdS nanoparticles was in the range of 12 nm and the observed morphology was spherical. The results indicated that the proteins, which contain amine groups, played a reducing and controlling responsibility during the formation of CdS nanoparticles in the colloidal solution. Antibacterial activity against some bacteria such as Bacillus subtilis, Klebsiella planticola. CdS nanoparticles exhibiting good bactericidal activity.

Antibodies are good escorts for a therapeutic and diagnostic tool against many diseases as well as for targeting drug delivery and in immunohistochemistry. Cysteine-capped cadmium sulfide (quantum dot) nanoparticles have wide applications in immunohistochemistry due to their unique physical, chemical, and fluorescent properties. In this study, polyclonal antibodies against transferrin (as ligand), doxorubicin (anticancer drug), and H. pylori (cancer-causing agent) were developed in rabbits and purified. Purified antibodies were labeled with cadmium sulfide (CdS) quantum dot (QD) and used as a fluorescent-labeled marker for one-step identification in diagnosis and therapeutics. Cysteine-capped CdS QDs were synthesized in the presence of taurine (antioxidant) and characterized by FTIR, VSM, DLS, and TEM. CdS nanoparticles are monodisperse with a narrow size range below 7 nm and showed an increase of almost 30 nm after conjugation to IgG. The binding of QD-labeled antibodies was observ...

Nanocrystalline Cadmium sulfide (CdS) thin films were prepared by chemical bath deposition technique on a glass substrates at  a temperature of 80°C  and at different deposition times with composition of cadmium chloride (CdCl2), thiourea (CS (NH2)2), ammonia solution (NH4OH) and triethanolamine (TEA) solution. The characterization of thin films was carried out for the structural, morphological and optical properties using X-ray diffraction (XRD), Scanning electron microscope (SEM) and UV-VIS spectrophotometer. XRD studies show that the preferential orientation (002), analysis shows that the prepared samples have hexagonal crystal structure. Scanning electron microscopy (SEM) reveals small nanosized grains tied up in a fibrous-like porous structure uniformly distributed over the surface of the substrate for the CdS films. A UV-VIS optical spectroscopy study was carried out to determine the band gap of the nanocrystalline CdS thin films. The average band gap was found to be 2.25 eV, ...

Full Article Figures & data References Citations Metrics Reprints & Permissions Get access ABSTRACT Effect of sonication time on the synthesis of the CdS nanoparticles within the matrix obtained through the covalent functionalization of multiwall carbon nanotube (MWCNT) with maleic anhydride (MA) – 1-octene copolymer was investigated. Cadmium chloride and thiourea were used as the raw materials. MWCNTs used for the matrix were synthesized by Catalytic Chemical Vapor Deposition using Fe-Co/Al2O3 as the catalyst. The obtained nanostructures were characterized by FTIR, XRD, Raman spectroscopy, TEM, SEM, TG and UV-Vis spectroscopy. Electrophysical properties of the polymer nanocomposites obtained using different periods of time for sonication were comparably investigated. The average CdS particle diameter was between 3.9–7.9 nm as confirmed independently by TEM and XRD. UV-Vis spectroscopy revealed that the obtained nanostructures are appropriate base materials for making optical devices.

In this paper, we discuss the synthesis of cadmium sulfide (CdS) quantum dots within thermally evaporated sodium bis(2-ethylhexyl)sulfosuccinate (AOT) thin films. This procedure uses electrostatic interactions to entrap positively charged cadmium ions into thin films of the anionic surfactant AOT by a simple immersion of the film in electrolyte solution. Thereafter, the composite film is treated with H 2 S gas/Na 2 S solution resulting in the in-situ formation of CdS nanoparticles in the quantum size regime. It is believed that the ability of AOT molecules in the thermally evaporated thin films to form reverse micelles is responsible for the CdS nanoparticle size control observed. Investigation of the entrapment of cadmium ions in the AOT film and subsequent quantum dot synthesis was carried out by quartz crystal microgravimetry (QCM), UV-Vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) measurements.

A novel hierarchical three dimensional (3D) NiO/CdS heteroarchitecture was successfully synthesized by a facile single pot hydrothermal route and characterized by powder X-ray diffractogram, UV-Vis spectroscopy, BET, FE-SEM and TEM. FE-SEM and TEM analysis ...

Cadmium sulfide nanowires were synthesized on in-situ generated alumina nanoparticles using a one pot hydrothermal method. As grown hexagonal-phase cadmium sulfide nanowires have diameters ranging from 40 to 50 nm. Mechanistic aspects reveal that the alumina template based growth of cadmium sulfide nanowires is due to the fact that S2− ions will preferably attach to the aluminum due to the Lewis acidic character of Al3+ (~ 0.5 on Brown's scale of average Lewis acid strength). To support the proposed mechanism, we have further shown the growth of cadmium sulfide nanowires on zinc ions having similar Lewis acidic strength.► This is the first growth method reported wherein the Lewis acidic character of a substrate has been explored in a growth technique. ► This method provides a pathway to generate device configurations in a wet chemical route. ► The mechanistic aspects proposed would give scope for further research in the field of nanowire growth.