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Cadmium sulfide (CdS) thin films (d=0.15–1.15 μm) were deposited onto glass substrates by the quasi-closed volume technique under vacuum. The investigations shown that the films are polycrystalline and have a hexagonal structure. It was experimentally established that the films with stable structure can be obtained if they are submitted to a heat treatment, consisting of several succesive heating/cooling cycles within a given temperature range (ΔT=300–600 K), the temperature dependence of the electrical conductivity becomes reversible. For heat-treated samples, the values of thermal activation energy calculated from the temperature dependence of the electrical conductivity, ranged between 2.30–2.45 eV. The spectral dependences of the transmission and absorption coefficients were studied in the range 500–1400 nm. The influence of heat treatment on the shape of the absorption spectra and dispersion index of refraction is studied for samples with different thickness. Optical energy gap, calculated from the absorption spectra was in the range 2.30–2.5 eV.

Present study is a computational approach focused on optical properties of Ni-doped rocksalt CdS system under PBE-GGA and GGA + U approximations. Investigation of optical properties of CdS:Ni system by fixing supercell size and increasing dopant concentration is a focus of study. Cd atoms are substituted by Ni atoms and optical properties show significant change for higher Ni concentration. Redshift in optical absorption is observed as dopant concentration is increased. Interaction of Ni and S atoms and localization of d-states are inspected near the conduction band minima or Fermi surface. GGA + U absorption plots show slight variation with increase in energy values. Ni-doping in CdS host lattice enhances its opto-electronic properties which extend its applications in optical sensors, optical and similar devices.

Current research is a computational study in which we focus on calculating optical properties of Eu-doped Cadmium Sulfide (CdS) system. We employ Perdew–Burke–Ernzerhof (PBE)–generalized gradient approximation (GGA) for accomplishment of our study and we assume various Eu concentrations (3.12%, 6.25% and 9.37%) for doping into host CdS lattice. We substitute Cd atoms with Eu atoms while supercell size is kept fixed ($1\times 2\times 2)$. We present a detailed comparison among optical properties of pure CdS and various Eu concentrations. Partial density of states (PDOS) plots reveal hybridization among Cd $s$-states, S $p$-states and Eu $d\text{–}f$-states and because of it, material (CdS:Eu) shows exceptional energy transfer which influences optical spectra and electronic properties. A considerable change in absorption spectra is noted, where in comparison to pure CdS, absorption shows blueshift with increasing Eu concentrations. Our DFT results were found to have great resemblance with existing literature. Addition of Eu into the CdS lattice originates novelty in CdS:Eu system and number of potential applications related to the field of biomedical physics, amperometric biosensors, quantum dots (QDs) sensors, photonics, bioprinting, biosensing luminophores, solar cells and optoelectronics industry may be explored in technological perspectives.

Cu-doped Cadmium sulfide (CdS) films were prepared by chemical bath deposition method. Various quantities of Cu were used for mixing. Surface characterization, structure, morphology and defect structures of the films were studied. The structure of all Cu-doped CdS films was a unique CdS cubic phase. The grain size of CdS was decreased when doped with Cu. The F-type defect in the undoped CdS is clearly confirmed by an ESR signal arising from the hyperfine interaction of electron spin (S=1/2) trapped in sulfur vacancies and neighboring cadmium nuclear spin (I=1/2). In the Cu-doped CdS films, the ESR peaks shift towards low fields as the copper concentration is increased. This is due to the change in crystal field experience by Cu²⁺ (3d⁹) ions while the Cd²⁺ signal disappears. The Cu²⁺ ions in the Cd_1-xCu_xS itself are ESR silent due to a very short relaxation time. The dark resistance increased with increasing amount of Cu concentrations up to about 0.03 M. This 0.03 M Cu-doped CdS sample also possesses the maximum photosensitivity.

A simply modified bath deposition technique has been successfully used to deposit uniform CdS thin films using cadmium chloride or cadmium acetate as the cadmium ion source, and thiourea as the sulfur source on glass substrates. Both the traditional magnetic agitation and the frequent substrate vibration by hand were done simultaneously during the deposition. Various properties of the deposited films such as surface morphology, crystallinity, and optical properties were investigated. The CdS films deposited from cadmium acetate show a good crystallinity and exhibit a preferential orientation along the hexagonal (002) direction. Their surface morphologies are more homogeneous with smaller grains than those from cadmium chloride. The CdS films prepared from both cadmium ion sources present a high optical transmission (more than 80%) in the visible range with the band gap value of about 2.4 eV. The substrate vibration reduces the formation and residence of gas bubbles on the glass substrate during growth and resulted in deposition of CdS thin films with high quality. XRD, SEM, and UV–Vis measurements have provided the supported data. The fundamental CBD growth mechanisms involving different cadmium salts are discussed.

Effects of buffer salt concentration on the rate of deposition, dominated deposition mechanism and subsequently the structural, morphological, and optical properties of cadmium sulfide (CdS) thin films deposited by chemical bath deposition (CBD) on glass substrate were investigated. The precursors were chosen to be cadmium chloride (CdCl₂) as the cadmium source, thiourea (CS(NH${}_2{)}_2$) as the sulfur source, ammonium nitrate (NH₄NO₃) as the buffer salt and ammonia as the complexing agent and the pH controller. The influence of the NH₄NO₃ concentration on the structure, morphology, film uniformity, stoichiometry and optical properties of CdS thin films was also studied by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray (EDX) spectroscope, uv–visible and photoluminescence (PL) spectroscopes. The XRD studies revealed that all the deposited films exhibited a (002)h/(111)c preferred orientation. The crystallite size was increased from 20nm to 30nm by the increase of concentration of NH₄NO₃ from 0.5M to 2.5M. The morphology of CdS thin films were agglomerated spherical particles consisted of smaller particles. The surface of thin films deposited at the NH₄NO₃ concentration of 0.5M was compact and smooth. The increase of the concentration of NH₄NO₃ decreased the packing density of the films. The optical band gap was in the range of 2.25–2.4eV, which was decreased by the decrement of packing density. The PL spectra showed two peaks centered at 400nm and 500nm which are attributed to violet and band-to-band emissions, respectively.

We report here our investigations on dark DC resistivity and optical absorption of chemical bath deposited CdS thin films prepared by chemical bath deposition. Crystallite sizes of about 30 nm are found from XRD using Scherrer formula with an added term for strain broadening. Energy-dispersive X-ray measurement shows correct stoichiometry of Cd and S atomic ratio. The grain size of the as-deposited film determined from both AFM and TEM is found to be ~180 nm. On vacuum annealing, the dark resistivity decreases from ~10⁹ to 10⁶ Ω-cm. Dark resistivity variation of as-deposited and vacuum-annealed films with temperature in the temperature region (95–350 K) reveals that each film exhibits two types of conduction in this temperature region. From the optical absorption study the optical band gap of as-deposited film is found to be ~2.29 eV.

A simple inexpensive wet chemical technique at room temperature to prepare hybrid structure of multiwalled carbon nanotubes (MWCNT) and cadmium sulfide (CdS) nanoparticles has been reported in this paper. Cadmium sulfide nanocrystals of average size 5 nm have been synthesized and attached with the surfaces of MWCNTs. The hybrid material is characterized by high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Raman spectroscopy. Interesting optical properties of the composite are revealed through UV–visible and photoluminescence (PL) spectroscopy. Significant blue-green PL emission covering a region from 450–600 nm wavelength has been observed when excited by UV radiation of 220–240 nm wavelength. Sharp emission peak has been obtained and this may find wide applications in optical sensors and optoelectronic devices.

We report here the UV-VIS study of CdS nanoparticles synthesized via Chemical precipitation in aqueous medium, the UV-VIS of CdS in aqueous medium shows an excitonic peak at 230 nm, while that of CdS quantum dots in solid form shows an absorption maximum at 480 nm. This bleaching of band gap may be attributed to Moss–Burstein shift in the absorbance edge.

One-dimensional (1D) single crystalline CdS nanostructures have been successfully synthesized via a diphenylthiocarbazone-assisted solvothermal route. The results revealed that the microstructure and optical absorption properties of 1D CdS nanostructures were temperature and time dependent owing to thermodynamically and kinetically controlled growth. Single crystalline CdS nanowires with a diameter of 80 nm and length of 20 μm were synthesized at 180°C for 96 h. At moderate temperature (180°C), the morphology of the products transformed from irregular short rods to uniform long rods as the reaction time prolonging in a kinetically controlled growth regime. Only nanorods were obtained at a temperature as low as 120°C even extending reaction time to 260 h due to thermodynamic limited growth. At high temperature (250°C in this system), the products were nanowires with larger diameter but lower aspect ratio since the growth rates on both lateral and axial directions were accelerated. Moreover, the optical absorption spectra revealed that the CdS nanowires showed a blue shift compared with bulk CdS. Two optical absorption peaks appeared due to the nanometer effect in the radial and lengthwise directions of CdS nanowires. The growth mechanism of 1D CdS nanostructures was discussed.

A photoelectrochemical (PEC) sensor for the determination of organophosphate pesticides (OPs) was developed based on rGO/TiO₂/CdS photoactive nanomaterials. The rGO/TiO₂/CdS nanocomposites were prepared by solvothermal method and electrochemical deposition technique successively. The morphologies and structures of the as-prepared nanocomposites were extensively investigated by SEM and XRD. In alkaline condition, p-nitrophenol as the hydrolysate of parathion-methyl (PM) could be obtained by a simple hydrolyzation process. Under optimal conditions, the rGO/TiO₂/CdS NPs modified ITO electrode exhibited a good PEC performance toward the hydrolysate of PM. The photocurrent intensity was enhanced with the increase of the concentration of the hydrolysate of PM. The proposed PEC method could detect PM in the range from 0.05nmol L${}^{-1}$ to 10nmol L${}^{-1}$ with a detection limit of 0.02nmol L${}^{-1}$ ($S∕N=3$). Thus, the excellent performance of the rGO/TiO₂/CdS nanocomposites serve as the matrix of the sensor, which provides a new way for the fabrication of high-sensitivity PEC sensing system.

Large-scale CdS nanorod arrays have been prepared directly by a simple one-step and non-template magnetron sputtering method on different substrates. Parallel and uniform CdS nanorods with diameters ∼ 70 nm were self-assembled with (00l) orientation regardless of the substrate. The CdS nanorod arrays showed high open-circuit photovoltage, short-circuit photocurrent intensity and excellent photosensitivity properties with a switching "ON/OFF" ratio as high as 60. This study provides a simple strategy to grow CdS nanorod arrays without the constraints introduced by the substrate and opens a new potential for the application of CdS nanorod arrays in photodetectors and nanostructured solar energy conversion devices.