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The reversibility of the covalent interaction between boronic acids and 1,2- or 1,3-diols has put the spotlight on this reaction for its potential in the development of sensors and for the fishing of bioactive glycoconjugates. In this work, we describe the investigation of this reaction for the reversible functionalization of the surface of CdSe/ZnS Quantum Rods (QRs). With this in mind, we have designed a turn-off Förster resonance energy transfer (FRET) system that ensures monitoring the extent of the reaction between the phenyl boronic residue at the meso position of a BODIPY probe and the solvent-exposed 1,2-diols on QRs' surface. The reversibility of the corresponding boronate ester under oxidant conditions has also been assessed, thus envisioning the potential sensing ability of this system. [ABSTRACT FROM AUTHOR]

In the present work, we have developed a rapid, cost-effective aqueous phase route to synthesize water-soluble Thioglycolic acid (TGA) capped CdSe/ZnS (CdSe/ZnS + TGA) QD sensor. Synthesized QD sensor has been successfully validated its candidature for the efficient detection of hazardous heavy metal ions (Xn+) specifically chromium (Cr3+) and copper (Cu2+) in aqueous medium. In the presence of Xn+ metal ions, "Turn-Off" fluorescence response is observed due to the complex formation (Xn+: CdSe/ZnS + TGA). A strong 1:1 complexation (Xn+: CdSe/ZnS + TGA) between QD sensor and Xn+ metal ion is confirmed by the output of Benesi–Hildebrand relation and Job's plot. As per our knowledge our proposed CdSe/ZnS + TGA QD sensor has established its efficient sensing capability for metal ions with lower detection of limit (LOD) up to concentration ~ 10–7 M for the first time which is lower than permissible limit as per WHO data. The practical application of this system for determining metal ions in real samples has also been successfully demonstrated. [ABSTRACT FROM AUTHOR]

Applying the cohesive energy model, this research theoretically studies how the size of nanoparticles affects their optical characteristics. The findings demonstrate that optical characteristics are size-dependent for nanoparticles, with an exponentially growing energy gap for nanoparticles on a scale of less than 4 nm. As the size of nanoparticles is reduced, the absorption wavelength also decreases. Compounds undergo a transition to a higher energy spectral area (blue shift) when their wavelength decreases; this change can make these compounds effective in certain optical nanodevices. [ABSTRACT FROM AUTHOR]

Copper Zinc Sulphide (Cu0.5Zn0.5S) alloy and thin films were fabricated in a vacuum. Nano crystallized (CZS) film with thick 450±20 nm was deposit at substrates glasses using thermal evaporation technique below ~ 2 x 10-5 mbar vacuum to investigated the films structural, morphological and optical properties depended on annealing temperatures ( as-deposited, 423, 523 and 623) K for one hour. The influences annealed temperature on structurally besides morphologically characteristics on these films were investigated using XRD and AFM respectively. XRD confirms the formation a mixed hexagonal phase of CuS-ZnS in (102) direction with polycrystalline in nature having very fine crystallites size varying from (5.5-13.09) nm. AFM analysis shows the uniform distribution of closely packed grains, grain size for that film diverge on ranges as of (52.37 to 89.25) nm after annealed. The optical properties of all films prepared had been examined for the wavelength range 400 - 1000 nm using UV-Vis-NIR spectrometer. The band gaps of (Cu0.5Zn0.5S) films are obtained in the range of 2.4 to 1.9 eV, which makes it a suitable absorber as well as buffer/window layer for solar cell applications. [ABSTRACT FROM AUTHOR]

In this work influence of capping and doping on the optical properties of the ZnS nanoparticles is studied. The Tinospora cordifolia was used as a capping agent and silver as a dopant for ZnS. The structural studies were carried out for phase identification and optical studies such as absorption and photoluminescence to check the influence of capping and doping. The shift in absorption edge and reduced photoluminescence intensity for these samples confirmed the interaction of capping and doping agents with the ZnS matrix. The presence of impurity phase-related to modified silver confirmed the presence of silver. These samples were further used for photocatalytic studies but observed low degradation efficiency due to poor interaction between the modified ZnS surface and dye molecules. [ABSTRACT FROM AUTHOR]

Abstract—Ultrafine ZnO–ZnS powder with d-metal oxide additions, namely, V2O5, MnO, Fe2O3, CoO, NiO, and CuO are studied. The alloying of the ZnO–ZnS system with d metals changes the morphology of the synthesized powders. The particle size distribution obeys a lognormal law. An addition of d metal oxide upon the synthesis of ZnO–ZnS composite shifts the maximum of the particle-size distribution to the larger sizes. The more probable particle size in the samples alloyed with iron and cobalt (530 nm) exceeds that of unalloyed samples (320 nm) by more than 1.6 times. All the synthesized samples are found to be characterized by excess oxygen. The zinc, sulfur, and oxygen contents in the unalloyed ZnO–ZnS compositions is 48.0, 12.8, and 39.2 at %, respectively. The synthesis of the ZnO–ZnS composition together with transition metal oxides does not change the hexagonal and cubic symmetry of zinc sulfide and hexagonal symmetry of the zinc oxide. The presence of iron leads to an increase in the coherent domain size of the ZnS phase. [ABSTRACT FROM AUTHOR]

Electroluminescence (EL) is an innovative technology in the lighting area. EL devices' main structure consists of a phosphor layer sandwiched between two electrodes. In this work, several alternating-current EL devices were developed by applying a set of sequential layers with combinations of in-house prepared inks and a commercially available ink as the phosphor layer. A flexible polyester textile substrate was functionalized with the inks by spray coating, after knife coating an interfacial layer directly on the surface. A thorough study was carried out on the phosphor layer composition to optimize the EL device performance, more precisely, illuminance intensity and illuminance homogeneity. The developed phosphor layer was composed of zinc sulfide doped with copper (between 30.0 and 38.1 wt%) and diluted by using a diluent at different concentrations (from 28.0 to 35.5 wt%). The best peak illuminance intensity of 61 lux was obtained when the phosphor ink presented a 35.4% ZnS:Cu ratio and was diluted with 33.0% diluent. This study aimed to determine the best formulation of the phosphor layer, which can be highly useful for further developments of EL devices, taking into account different applications in the market. [ABSTRACT FROM AUTHOR]

Surface energy is a fundamental property of materials and is particularly important in describing nanomaterials where atoms or molecules at the surface constitute a large fraction of the material. Traditionally, surface energy is considered to be a positive quantity, where atoms or molecules at the surface are less thermodynamically stable than their counterparts in the interior of the material because they have fewer bonds or interactions at the surface. Using calorimetric methods, we show that the surface energy is negative in some prototypical colloidal semiconductor nanocrystals, or quantum dots with organic ligand coatings. This implies that the surface atoms are more thermodynamically stable than those on the interior due to the strong bonds between these atoms and surfactant molecules, or ligands, that coat their surface. In addition, we extend this work to core/shell indium phosphide/zinc sulfide nanocrystals and show that the interfacial energy between these materials is highly thermodynamically favorable in spite of their large lattice mismatch. This work challenges many of the assumptions that have guided thinking about colloidal nanomaterial thermodynamics, investigates the fundamental stability of many technologically relevant colloidal nanomaterials, and paves the way for future experimental and theoretical work on nanocrystal thermodynamics. [ABSTRACT FROM AUTHOR]

Multifarious novel photocatalysts based on hybrid nanocomposites have been developed to boost photocatalytic efficiency. However, the photocatalytic property of hybrid nanocomposites is still bound by inferior thermal stability, tardive charge motion kinetics and few active sites. In this work, a convenient and facile cation exchange approach was conceptually provided for fabricating a well-designed and robust P–N heterojunction based on Mn–Zn–S–ethylenediamine hybrid nanocomposite. Such hybrids take ZnS–ethylenediamine as the skeleton, and the Mn2+ cations are superseded and inserted into the interlayer of ZnS through the cation exchange approach, thus forming the Mn–Zn–S–ethylenediamine hybrid nanocomposite. Hence, as-synthesized ZnS–Mn1.0 had a significantly promoted photoactivity for reducing p-nitroaniline (94.5%) and p-nitrotoluene (88.6%) to the corresponding amino derivatives, besides oxidizing phenol (94.6%) under simulated solar irradiation. Meanwhile, PEC measurements illustrated that the interface created by this cation exchange approach was beneficial to promoting the motion behavior and prolonging the lifetime of photo-generated charges. Through this work we hope to offer an emerging strategy to finely design and fabricate all hybrid nanocomposite-based heterostructured photocatalysts for enhancing solar-to-chemical energy conversion. [ABSTRACT FROM AUTHOR]

[Display omitted] • The porous lamellar GO/Ni 2 ZnS 4 @NiCo 2 S 4 was prepared using simple ZIF-8@ZIF-9 templating method. • The core–shell structure of graphene trimetallic sulfides was synthesized for the first time. • GO/Ni 2 ZnS 4 @NiCo 2 S 4 inherits the high specific surface area of the ZIF template and the high pseudocapacitance of the sulfide. • High specific capacity of 2284F/g were achieved at the current density of 1 A/g. Metal-organic frameworks (MOFs) have emerged as promising active electrode materials in supercapacitors for its controllable porous structure and excellent physio-chemical properties. However, the poor conductivities keep it from achieving its full capacitance potential, which greatly limits its practical application. Here, a facile pathway is reported to fabricate the GO/Ni 2 ZnS 4 @NiCo 2 S 4 composite with large specific surface area and favorable electrical conductivity. Thanks to the novel tremella-like core–shell structure and high-efficient synergistic effects among multi-components, the designed GO/Ni 2 ZnS 4 @NiCo 2 S 4 electrode shows a high specific capacitance of 2284 F/g at 1 A/g. Furthermore, the asymmetric supercapacitor fabricated by coupling GO/Ni 2 ZnS 4 @NiCo 2 S 4 positive electrode with biological carbon negative electrode achieves a remarkable energy density of 120 Wh kg−1 at a power density of 750 W kg−1. [ABSTRACT FROM AUTHOR]

Zinc sulfide (ZnS) is widely employed in a solar cell structure as a buffer layer due to its excellent physical and chemical properties. ZnS elements discovered in the earth's crust are safe. This study examined the performance characteristics of ZnS thin films deposited on soda lime glass substrate via chemical bath deposition. The ZnS thin films were annealed at temperatures of 300, 400, and 500 °C in a vacuum environment. XRD showed the ZnS thin films with high annealing temperatures are composed of a wurtzite structure. Increased annealing temperature improved crystallization, average crystallite sizes, film thickness, and low dislocation density as well as lattice strain. The FESEM analysis reveals that the morphology of annealed thin film at high temperatures has larger grains compared to the deposited films. EDS spectra confirm that zinc and sulfur are present in the ZnS thin film. Annealed films have an average transmission of 20–50 % in the visible spectrum of 300–1100 nm. Films exhibit 103 Ωcm resistivity, and the bulk carrier density ranges between 1012 and 1014 cm−3. The annealed film at 500 °C has a direct band gap of 3.47 eV, a resistivity of 1.79 × 103 Ωcm, and a bulk concentration of 1.19 × 1014 cm−3. All ZnS thin films have n-type conductivity. [ABSTRACT FROM AUTHOR]

In this study, we synthesised and characterised a new zinc(II) triazenide for potential use in vapour deposition of zinc sulphide thin films. The compound is volatile and quantitatively sublimes at 80 °C under vacuum (0.5 mbar). Thermogravimetric analysis showed a one-step volatilisation with an onset temperature at ∼125 °C and 5% residual mass. The compound also reacted with 2 or 4 molar equivalents of triphenylsilanethiol to give dimeric and monomeric zinc thiolates, respectively. The high volatility, thermal stability, and reactivity with sterically hindered thiols makes this compound a potential candidate for use in vapour deposition of zinc containing thin films. [ABSTRACT FROM AUTHOR]

In the present work CdS, Cd0.75Zn0.25S, Cd0.5Zn0.5S, Cd0.3Zn0.7S, ZnS nanoparticles are grown by chemical reduction route using tetrahydrofuran (THF) as capping agent. The grown nanoparticles are characterized through structurally (XRD, FESEM, EDX) and optically (Optical absorption, emission and Raman Spectrum, TCSPC). X-ray diffraction peaks showed that the crystal structural phase transition from hexagonal phase to cubic phase as Zn content increases in nano-crystalline CdxZn1−xS. Other than CdS and ZnS, composition like Cd0.7Zn0.3S, Cd0.5Zn0.5S, Cd0.3Zn0.7S is targeted to grow and the obtained composition is specified through EDAX analysis. FESEM images show that surface morphology changes (nanorod to nanoparticles) with change of composition. Optical absorption study showed that nanoparticles are formed and the band gap varies from ≈ 2.49 eV for CdS NRs to ≈ 4 eV for ZnS NPs. Photoluminescence peak shifts from 469 nm to 410 nm with the increase of Zn content. TCSPC study shows that average lifetime decreases from 8.3 ns to 1.2 ns as the composition change from CdS NRs to ZnS NPs. Raman spectrum study showed blue shift i.e. from ≈ 301.7 to 314 cm−1 with change of composition. Using the grown nanoparticles as catalyst we present a photocatalytic degrdation technique of methylene blue (MB) dye in this paper. The results showed that photocatalytic degradation is maximum (86%) in presence of CdS nanorods (NRs) and it is drastically reduced (up to 30%) with ZnS nanoparticles (NPs) under the illumination of visible light. Thus Photo-degradation of methylene blue dye is enhanced in presence of CdS NPs but the activity is reduced as Zn content increases in CdxZn1−xS. The increase of photocatalytic activity is influenced by the shape of nanoparticles, band parameters, optical parameters and different optical light response, crystalinity as well as the lifetime of carriers. [ABSTRACT FROM AUTHOR]

In this paper, experiments on laser ablation of ZnS in atmospheric air using laser pulses with different energies and durations have been carried out. In the process of ablation processing, zinc sulfide nanoparticles with different stoichiometric ratio of elements were obtained. By varying the parameters, it is possible to control changes in the size of nanoparticles and their composition. As a result of studies of synthesized nanoparticles, Raman scattering spectra, energy dispersion analysis results, and images of deposited nanoparticles were obtained. Conclusions are drawn about the suitability of nanopowder synthesis approaches for the subsequent production of stable colloidal solutions. [ABSTRACT FROM AUTHOR]

The heavy metals present in the sludge can undergo a reaction with sulfur, leading to their conversion into metal sulfides through hydrothermal sulfidation. Sulfur ions, possessing a strong sulfidation capability, can operate within a wider pH range at elevated temperatures. The high temperature environment promotes the sulfidation process of zinc within heavy metal-laden sludge. Increasing the temperature of microwave hydrothermal sulfidation and extending the sulfidation duration for heavy metal-containing sludge can enhance the growth of crystal size in the artificially synthesized zinc sulfide. Zinc sulfide predominantly takes the form of ZnS, which facilitates the subsequent flotation recovery of zinc. [ABSTRACT FROM AUTHOR]

Ternary composites, featuring TiO2 as a key component, have gained recognition for their exceptional photocatalytic performance in water treatment. In this study, we investigated the effectiveness of TiO2/ZnS/GO composites, both in powdered and immobilized forms, for the removal of single and mixed dye pollutants, including methylene blue (MB), methyl orange (MO), and Rhodamine B (RhoB). Comprehensive characterizations utilizing various spectroscopic and microscopic techniques confirmed the successful fabrication of TiO2/ZnS/GO composites. The findings revealed that the composite achieved impressive individual removal rates of 98.4%, 83.6%, and 95.7% for MB, MO and RhoB, respectively, through adsorption and photocatalytic effects. In the case of co-existing dyes, the composite eliminated 99.1%, 44.3%, and 62.1% of MB, MO and RhoB, respectively. Furthermore, when incorporated into alginate, TiO2/ZnS/GO–CaAlg beads displayed exceptional dye adsorption capacity and facilitated easy recovery from the reaction medium. This engineered TiO2/ZnS/GO composite exhibits significant potential in both its powdered and bead forms, particularly due to its superior adsorption capabilities compared to its photocatalytic effects. These findings offer valuable insights into its prospective application in wastewater treatment, with a key emphasis on its efficiency in simultaneously tackling multiple pollutants. [ABSTRACT FROM AUTHOR]

Inorganic semiconductors have been considered to be brittle at room temperature generally, but recently zinc sulfide (ZnS), a II-VI compound semiconductor, was found to exhibit extraordinarily large plasticity even at room temperature if itwas deformed in darkness. Room-temperature plastic deformation can achieve high density of glide dislocations in the crystalwithout significantly changing the point defect structure, and these dislocations themselves have a potential to provide unique functional properties different from those of the bulk. In this study, therefore, undoped ZnS crystals were plastically deformed at room temperature in darkness to generate only a large number of dislocations, and the changes in luminescence properties resulting fromthis processwere investigated for the first time. As a result, we found that ZnS deformed in darkness exhibits characteristic photoluminescence and persistent luminescence emissions with a visible green color. SEM-CL analyses also identified the emissions from the dislocations. Theoretical calculations indicated that individual dislocations in ZnS have the ability to trap photo-excited carriers. Such changes in luminescence properties due to room temperature plastic deformation in darkness can be considered to originate from dislocations rather than point defects. In other words, the dislocations themselves serve as the significant recombination centers, realizing visible light emission. [ABSTRACT FROM AUTHOR]

The possibility of selective Cu and Zn leaching from the sample of old pyrite tailings, which is one of the most widespread types of solid waste forming during non-ferrous metal production, using sulfuric acid solutions and water was studied. It was shown that water leaching provided selective extraction of Cu and Zn and comparatively low iron ion extraction. At the same time, acid leaching provided the obtainment of pregnant solutions with high ferric ion concentration, which can be used for oxidative leaching of substandard copper concentrates. Water and acid leaching also provided increased Au recovery by cyanidation. The results suggest that acid leaching can be an effective approach for processing old flotation tailings, which allows the extraction of base metals from these wastes and treating flotation tailings for subsequent cyanidation. Effective flotation treatment methods should also provide environmental load reduction, which is caused by the long-term storage of metal-bearing wastes. [ABSTRACT FROM AUTHOR]

TiO2 and ZnO films were synthesized by the dip-coating method. The coupling of thin films of metal sulfides: CuS and ZnS by thermal evaporation in each semiconductor oxide was analyzed. TiO2, CuS/TiO2, ZnS/TiO2, ZnO, CuS/ZnO, and ZnS/ZnO samples were analyzed by X-ray diffraction, Raman microscopy, atomic force microscopy, UV-Vis spectroscopy, and photoresponse. The optical and morphological analysis revealed that the CuS/TiO2 and CuS/ZnO samples present better properties than the pristine samples. This was attributed to the fact that their absorption edges move to lower energy regions and their roughness increases refraction, so there is a greater photoelectric response due to the accumulation of photo-injected electrons in the conduction band. [ABSTRACT FROM AUTHOR]

Cadmium sulfide and zinc oxide nanoparticles were prepared, characterized and used as electrode modifiers for the sensing of two non-steroidal anti-inflammatory drugs (NSAIDs): naproxen and mobic. The structural and morphological characterization of the synthesized nanoparticles was carried out by XRD, UV-Vis spectroscopy, FTIR and scanning electron microscopy. The electrode's enhanced surface area facilitated the signal amplification of the selected NSAIDs. The CdS-modified glassy carbon electrode (GCE) enhanced the electro-oxidation signals of naproxen to four times that of the bare GCE, while the ZnO-modified GCE led to a two-fold enhancement in the electro-oxidation signals of mobic. The oxidation of both NSAIDs occurred in a pH-dependent manner, suggesting the involvement of protons in their electron transfer reactions. The experimental conditions for the sensing of naproxen and mobic were optimized and, under optimized conditions, the modified electrode surface demonstrated the qualities of sensitivity and selectivity, and a fast responsiveness to the target NSAIDs. [ABSTRACT FROM AUTHOR]

Soft robots require soft actuators for mobility and functionality. To integrate multiple functions in a limited space, researchers are developing multifunctional soft actuators with several functions integrated in one device. This study successfully demonstrates an electroluminescent (EL) soft actuator, a single device with both light‐emitting and actuating capabilities, using liquid dielectric and uniformly dispersed EL phosphor particles. EL phosphor particles are copper‐doped zinc sulfide (ZnS) particles doped with copper. The work is able to disperse the ZnS particles uniformly in the oil by coating the ZnS particles with silica, ensuring consistent luminescence across the device's active area. The performance of the soft actuator is notable, with a strain of 25% and a maximum EL intensity of 23 cd m−2 for a single actuator. When stacking multiple actuators, the intensity exceeds 29 cd m−2. The findings suggest that EL actuator devices will be valuable smart components for soft robots and interactive sensors. They can effectively represent external stimuli through color signals, expanding the capabilities of these systems. [ABSTRACT FROM AUTHOR]

In this study, the use of intrinsic and highly insulating ZnO buffer layers to achieve high conversion efficiencies in CdSeTe/CdTe solar cells is reported. The buffer layers are deposited on commercial SnO2:F coated soda‐lime glass substrates and then fabricated into arsenic‐doped CdSeTe/CdTe devices using an absorber and back contact deposited by First Solar. The ZnO thickness is varied from 30 to 200 nm. The devices incorporating a 50 nm ZnO buffer layer achieved an efficiency of 21.23% without an anti‐reflection coating. An improved efficiency of 21.44% is obtained on a substrate with a multilayer anti‐reflection coating deposited prior to device fabrication. The highly efficient ZnO based devices are stable and do not develop anomalous J‐V behavior following environmental tests. High resolution microstructural analysis reveals the formation of a high‐quality ZnO/CdSeTe interface. Unusually, chlorine is not detected as a discrete layer at the interface, these observations point to a high‐quality interface. The extrapolation of Voc to 0 K indicates that interface recombination dominates, suggesting that further improvement is possible. Using device modeling, an attempt is made to understand how this type of device performs so well. [ABSTRACT FROM AUTHOR]

2D/2D semimetal 1T′ phase MoS 2 /ZnIn 2 S 4 (1T′-MoS 2 /ZnIn 2 S 4) S-Scheme heterojunction has been prepared by a simple hydrothermal method. The 1T′-MoS 2 /ZnIn 2 S 4 2D/2D S-Scheme heterojunction presents excellent photocatalytic activity for hydrogen production without the addition of noble metal co-catalysts. [Display omitted] Heterojunction engineering is an effective strategy to improve photocatalytic performance. Two-dimensional (2D)/2D semimetal 1T′ phase molybdenum sulfide/zinc indium sulfide (1T′-MoS 2 /ZnIn 2 S 4) S-scheme heterojunctions with tight and stable interfaces were synthesized by a simple hydrothermal synthesis method. Under the optimal 1T′-MoS 2 loading ratio (5 wt%), the hydrogen production rate of 1T′-MoS 2 /ZnIn 2 S 4 composites reaches 11.42 mmol h−1 g−1, which is 3.1 and 1.4 times higher than that of pure ZnIn 2 S 4 (2.9 mmol h−1 g−1) and ZnIn 2 S 4 /Pt (8.01 mmol h−1 g−1), and the apparent quantum efficiency (AQE) reaches 53.17 % (λ = 370 nm). Semimetal 1T′ phase MoS 2 on ZnIn 2 S 4 broadens the light absorption range, enhances the light absorption ability, promotes electron transfer, and offers abundant active sites. The establishment of S-scheme heterojunctions achieves the spatial separation of photogenerated charges and increases the reduction potential. This work provides insights for the design of novel photocatalysts. [ABSTRACT FROM AUTHOR]

This article deals with the optimization by simulation of a graded bandgap thin film solar cell based on antimony selenosulfide Sb2(Se1-ySy)3 having the following structure: Front contact/n-ZnO/i-ZnO/p-SbSSe/n-CdS/Back contact. The simulation is performed using SCAPS-1D software. The optimization process includes optimizing the bulk defect density, bandgap profile, material composition, thickness, and doping density of the absorber layer of thin film solar cell based on antimony selenosulfide Sb2(Se1-ySy)3. We found that for a bulk defect density below 1013 cm-3, using an absorber material with a graded bandgap profile leads to an efficiency of 25.33 % (For a bulk defect density of 1010 cm-3) higher than that with a uniform bandgap profile. However, for a bulk defect density of 1013 cm-3, both profiles provide almost the same maximum solar cell conversion efficiencies of about 13.6 %. Ultimately, for a bulk defect density above 1013 cm-3, the graded bandgap profile is not useful, and a maximum solar cell conversion efficiency of 10.5 % (For a bulk defect density of 1014 cm-3) is achieved with a uniform bandgap profile. These optimization results help to improve the efficiency of low-cost fabricated thin-film solar cells. [ABSTRACT FROM AUTHOR]

In this work, the gas sensing properties of ZnS/Porous silicon heterostructures have been investigated. . Zinc sulfide(ZnS) with high gas sensing performance is successfully synthesized over the Porous silicon substrate by the spray pyrolysis method. The properties of the as-prepared samples were characterized X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform spectrum (FTIR) and optical properties. The results reveal that the properties of the ZnS/Porous silicon heterostructures enhanced when the when the ZnS concentration is increased. The performance ZnS/Porous silicon as a gas-sensing show that the maximum sensitivity is found to be 5.11 at ZnS concentration of 0.5 M and etching time of 15 min compared to the other sensitivities. The ZnS-PSi heterojunction based gas sensor may be used for UV-light photo-detectors due to a valuable properties such as high sensitivity and fast response. [ABSTRACT FROM AUTHOR]

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This study explores the potential of four types of nanoparticles (ZnO, ZnS, FeS2, and SnO2) to combat resistant microbes using the well method. The research focuses on their antifungal and antibacterial properties. Results showed that FeS2 and ZnO nanoparticles displayed broad-spectrum activity against various bacteria and fungi. This was evident by the formation of clear inhibition zones after 24 h at 37°C. These findings highlight the promise of FeS2 and ZnO nanoparticles as weapons against resistant microbes. The inhibition zones demonstrate a measurable effect on microbial growth, providing valuable groundwork for further development of novel strategies to fight and manage microbial infections. This research adds to the ongoing search for alternative and effective solutions in the face of growing microbial resistance. [ABSTRACT FROM AUTHOR]

Hafnium carbide (HfC) is a refractory compound known for its exceptional mechanical, thermal, and electrical properties. This compound has gained significant attention in materials science and engineering due to its high melting point, extreme hardness, and excellent thermal stability. This study presents crystal structure prediction via energy landscape explorations of pristine hafnium carbide supplemented by data mining. Apart from the well-known equilibrium rock salt phase, we predict eight new polymorphs of HfC. The predicted HfC phases appear in the energy landscape with known structure types such as the WC type, NiAs type, 5-5 type, sphalerite (ZnS) type, TlI type, and CsCl type; in addition, we predict two new structure types denoted as ortho_HfC and HfC_polytype, respectively. Moreover, we have investigated the structural characteristics and mechanical properties of hafnium carbide at the DFT level of computation, which opens diverse applications in various technological domains. [ABSTRACT FROM AUTHOR]

Particles composed of zinc oxides were prepared by changing the synthesis parameters in a glycerol-based solvent. By varying the mole ratio of zinc nitrate and sodium hydroxide in a glycerol–urea solvent, unexpected Zn5(OH)8(NO3)2·2H2O intermediate and ZnO wurtzite phases were identified at different percentages depending on the reactant stoichiometry and temperature. Exchanging urea for isopropanol, tetramethyl urea, dimethylurea, thiourea, and ammonia gas provided different resultant materials. Dimethylurea and tetramethyl urea led to ZnO nanoparticles though passing through the usual Zn(OH)2 intermediate, whereas thiourea formed only ZnS nanoparticles. Glycerol–isopropanol (GI) yielded ZnO nanoparticles with a small size distribution over a range of GI molar ratios. Bubbling ammonia into glycerol formed needle-shaped ZnO particles. These outcomes highlight the valuable synthetic potential of glycerol-based solvents that allow for highly efficient synthesis of tailored zinc-made particles with easy and mild work-up. [ABSTRACT FROM AUTHOR]

In this work, zinc sulfide (ZnS) QDs were synthesized using green technique with the help of Tabernaemontana divaricata flower extract as capping/stabilizing agent, characterized by different physical techniques, like XRD, FESEM, EDX, TEM, FT-IR, XPS, UV–Vis–NIR, and PL, and were compared with their pristine analogue. From XRD analysis, it is observed that the size of the synthesized ZnS QDs lie in 1.79–1.46 nm range and with addition of flower extract particle size decreases. FT-IR analysis indicated the functional groups present in the synthesized QDs. The direct energy band gap (3.21–3.51 eV) values as well as the refractive index values (2.28–2.33) of the QDs were calculated utilizing the absorption data. Due to various defect levels present in the ZnS QDs within the energy band gap, four peaks (three in visible and the other in NIR region) were observed in the PL spectra. Surface morphology and elemental composition of the particles were understood from FESEM and EDX studies. Dielectric constant, loss, and ac and dc conductivity of the materials were studied. At room temperature, all synthesized ZnS materials exhibited high dielectric constant ( ε r ) values in the low-frequency region. It is found that ε r values for pristine ZnS QD (~ 23,000) are much higher than the green ZnS QDs (~ 100–800) where overall dielectric loss is less than 2 which decreases with QD size. Results obtained from the characterization studies conducted on pristine and green-synthesized ZnS QDs elucidate that it is possible to effectively control the size, optical, and dielectric properties of the potentially important ZnS QDs through green synthesis technique. [ABSTRACT FROM AUTHOR]

Typically, the photoluminescence spectra of ZnS nanostructures exhibit a blue emission band and this material is commonly doped with Cu2+ ions to produce a green band and with Mn2+ ions to yield a yellow-orange band for LEDs applications. In this paper, we exclusively focus on Mn-doped ZnS/ZnO microbelts fabricated by a thermal evaporation method. The presence of the ZnO phase in the microbelts without active oxidation of the samples after synthesis influenced the optical properties of the microbelts. Photoluminescence of the prepared microbelts can be turned from a green to an orange band by changing the ratio between MnCl2 and ZnS powder. Especially, at a precursor ratio of 0.5:1, the neutral white light encompasses blue, green, and orange bands that appear simultaneously. When the content of MnCl2 equals that of ZnS powder, a high-value color purity (93.88%) can be achieved for the orange emission. The energy transfer mechanism between the ZnS host lattice, ZnO phase and the Mn2+ dopant will also be discussed in detail. [ABSTRACT FROM AUTHOR]

The synthesis of undoped and copper doped ZnS nanoparticles (NPs) by a facile starch mediated microwave assisted hydrothermal route is reported in this work. Polycrystalline, cubic ZnS nanostructure of the samples were revealed by X-ray diffraction studies. High resolution transmission electron microscopy (HRTEM) analysis revealed the crystalline nature of NPs with size distribution in 2–7 nm range. Analysis of X-ray emission induced by particles of samples indicated presence of copper content in the sample. Cu doping showed a strong influence on the green emission properties of the ZnS NPs under UV light illumination. The band gap values determined from UV–Vis absorption studies were higher than that for bulk ZnS (3.68 eV), confirming quantum confinement effect. Further, starch capping and Cu doping confirmed by Fourier transform infra-red (FTIR) spectra. A strong PL emission around 507 nm observed due to carrier transition from conduction band of ZnS to Cu2+ t 2 level. The intensity of this peak reduced at high dopant concentration due to quenching. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS 2) contains inactive basal and edge planes, which hinders its effectiveness in facilitating environmentally clean Hydrogen Evolution Reaction (HER) in electrocatalytic water splitting. Herein, we report a single-step synthesis strategy for developing ZnS–ZnO–MoS 2 /Ti 3 C 2 T x MXene (ZZM/MX) nanostructures through a hydrothermal approach. The SEM micrographs clearly demonstrate edge plane modification in MoS 2 , making them sharper and more exposed outward. XRD analysis exhibited the formation of ZnS and ZnO phases over MoS2 surface which was further supported by XPS analysis. The molar percentage of Zn precursor was increased from 1 % to 6 % and the resultant samples were designated as ZZM/MX-1, ZZM/MX-2, ZZM/MX-4, and ZZM/MX-6, respectively. Among the prepared samples, ZZM/MX-4 electrocatalyst exhibited the least overpotential of 327.6 mV @ 10 mA cm−2; and a low Tafel slope of 79.5 mVdec−1 in 0.5 M H 2 SO 4 electrolyte for HER. Also, it demonstrated excellent stability, withstanding 50 h of operation under acidic conditions. The higher electrocatalytic performance in this material can be attributed to the robust interaction between hetero-phase interfaces along ZnS–ZnO–MoS 2 and MXene (Ti 3 C 2 T x) support, which activates MoS 2 basal planes and enhances the charge transfer properties. Further, the activation of MoS 2 edges by introduction of ZnS/ZnO phases led to enhanced number of active sites for HER electrocatalysis. This work showcases an opportunity to apply dual modification of edge and basal planes in various other chalcogenide materials to enhance environmentally friendly clean HER performance and stability. [Display omitted] • Development of HF-Free environmentally safe method of Mxene etching. • Successful formation of MoS2/Mxene composite through mild hydrothermal approach. • Physicochemical Characterization evidenced the formation of Zn doped MoS2/Mxene. • Doping of MoS2/Mxene with Zinc improved electrochemical HER performance. [ABSTRACT FROM AUTHOR]

Although SnO2 has been widely used as the electron transport material (ETM) of the perovskite solar cells (PSCs), the energy level mismatch at the SnO2/CsPbBr3 buried interface is as high as 1 eV, which is disastrous for the CsPbBr3‐based PSCs. Herein, a buffer layer of metal sulfide (CdS, ZnS) is introduced to solve this problem. The power conversion efficiency (PCE) of CsPbBr3 PSCs has been increased from 8.16% to 9.48% for ZnS‐treated SnO2 (ZnS‐SnO2), and a champion efficiency of 10.61% has been achieved in CdS‐treated SnO2 (CdS‐SnO2) devices. Aside from the reduced energy loss, the mobility of the SnO2 ETM has been greatly enhanced after the metal sulfide treatment. The CdS‐SnO2 devices also enjoy the benefits of reduced defect density and speeded carrier extraction, contributing to an almost 30% performance enhancement. This 10.61% PCE is among the highly efficient CsPbBr3‐based PSCs reported to date. Finally, CdS‐SnO2 devices survive a harsh damp heat test (120 °C with a relative humidity of 50%) for a month with less than 15% efficiency loss, demonstrating the superior stability of our CsPbBr3 PSCs. [ABSTRACT FROM AUTHOR]

Solar-driven water splitting by inorganic semiconductor photocatalysts is considered a promising method to produce hydrogen fuel. Loading inorganic semiconductor on cellulose fiber to construct photocatalytic paper contributes to the dispersion and recycling of photocatalyst. In addition, the photocatalytic paper floating on water can build a solid–gas biphase photocatalytic interface (photothermal-generated steam/photocatalytic paper/hydrogen), replacing the traditional liquid–solid–gas triphase photocatalytic interface (liquid water/photocatalyst/hydrogen) for improving photocatalytic kinetics. Here, we design and synthesize a photocatalytic composite paper with zinc sulfide (ZnS) anchored onto cellulose fibers (CF) with the help of polydopamine (PDA). PDA achieves high load and uniform distribution of ZnS on cellulose fibers, and forms the ZnS/PDA heterojunction to increase photogenerated charge separation efficiency and photocatalytic stability. Solid–gas biphase photocatalytic interface constructed by the CF/PDA/ZnS composite paper minimizes the interface barriers of hydrogen transport and water molecular adsorption for improving hydrogen evolution rate. The CF/PDA/ZnS composite paper shows a high hydrogen production rate up to 18706.8 μmol h−1 g−1. Stable loading of ZnS/PDA heterojunction in composite paper contributes to the photocatalytic stability. In the third photocatalytic cycle, the hydrogen evolution rate of CF/PDA/ZnS composite paper remains 96.4%. This work inspires that anchoring of inorganic semiconductor on cellulose fibers with the help of PDA can be a promising strategy for designing efficient photocatalytic paper for solar hydrogen production. [ABSTRACT FROM AUTHOR]

In recent years, the growing concern over the presence of toxic aquatic pollutants has prompted intensive research into effective and environmentally friendly remediation methods. Photocatalysis using semiconductor quantum dots (QDs) has developed as a promising technology for pollutant degradation. Among various QD materials, indium phosphide (InP) and its hybrid with zinc sulfide (ZnS) have gained considerable attention due to their unique optical and photocatalytic properties. Herein, InP and InP/ZnS QDs were employed for the removal of dyes (crystal violet, and congo red), polyaromatic hydrocarbons (pyrene, naphthalene, and phenanthrene), and pesticides (deltamethrin) in the presence of visible light. The degradation efficiencies of crystal violet (CV) and congo red (CR) were 74.54% and 88.12% with InP, and 84.53% and 91.78% with InP/ZnS, respectively, within 50 min of reaction. The InP/ZnS showed efficient performance for the removal of polyaromatic hydrocarbons (PAHs). For example, the removal percentage for naphthalene, phenanthrene, and pyrene was 99.8%, 99.6%, and 88.97% after the photocatalytic reaction. However, the removal percentage of InP/ZnS for pesticide deltamethrin was 90.2% after 90 min light irradiation. Additionally, advanced characterization techniques including UV–visible spectrophotometer (UV–Vis), photoluminescence (PL), X-ray diffractometer (XRD), energy-dispersive spectrometer (EDS) elemental mapping, transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) were used to analyze the crystal structure, morphology, and purity of the fabricated materials in detail. The particle size results obtained from TEM are in the range of 2.28–4.60 nm. Both materials (InP and InP/ZnS) exhibited a spherical morphology, displaying distinct lattice fringes. XRD results of InP depicted lattice planes (111), (220), and (311) in good agreement with cubic geometry. Furthermore, the addition of dopants was discovered to enhance the thermal stability of the fabricated material. In addition, QDs exhibited efficacy in the breakdown of PAHs. The analysis of their fragmentation suggests that the primary mechanism for PAHs degradation is the phthalic acid pathway. [ABSTRACT FROM AUTHOR]

CdxZn1−xS nanoparticles have been synthesized on the base of functionalized nitrile butadiene rubber (FNBR) by SILAR method and characterized by various techniques. Both binary and ternary sulfide nanocrystals have been obtained in the cubic phase with very high purity at room temperature. The average particle size decreased from 2.49 nm to 2.22 nm and then increased to 2.44 nm by the increasing of zinc concentration from 25 % to 50 % and 75 %. The calculated Young's modulus for (111), (220) and (311) planes are 97.84, 78.51 and 64.33 m2 N−1 for CdS and 95.84, 69.68, 53.42 m2 N−1 for ZnS, respectively. The band corresponding PO32− (977 cm−1) shifted to 969, 975, 972, 973, and 972 cm−1 upon the formation of CdS, ZnS, Cd0.5Zn0.5S, Cd0.75Zn0.25S and Cd0.25Zn0.75S nanoparticles into FNBR matrix, which is explained by Hooke's Law. EPR spectra of CdS/FNBR nanocomposite show broad and singlet asymmetric, isotropic symmetry (gx=gy=gz). The appearance of a new line in the 3518 G magnetic field is observed in both CdS and Cd0.5Zn0.5S compounds' spectra.The total mass loss of the samples NBR, FNBR, Cd2+ and Zn2+ ions containing FNBR are 93.76, 59.77, 60.03 and 57.79 %, respectively. High crystallinity is caused by complete interaction of metal ions with functional groups during the nucleation. [ABSTRACT FROM AUTHOR]

Zinc oxide sulphide Zn (O, S) buffer layer has attracted enormous attention due to its composition of non‐toxic, low cost, and earth abundant elements, unlike cadmium sulphide (CdS) used in copper zinc tin sulphide (CZTS) solar cells. Zn (O, S) possesses a direct optical bandgap that's adjustable between 2.7 and 3.6 eV related to the mole fraction x=S/(S+O)$x = \text{S} / \left(\right. \text{S} + \text{O} \left.\right)$, making it a potential candidate as a buffer layer with CZTS based solar cells. In this work, the Zn (O, S)/CZTS‐based solar cell structure is numerically studied and compared with CdS/CZTS. The existence of defects and traps along the layers and interfaces is taken in consideration. To achieve optimal results, this research has focused on; effects of the element composition (x = S/(S + O)) ratio of Zn (O, S) buffer layer, the addition of a back surface field (BSF) layer, the influence of Zn (O, S)/CZTS and CdS/CZTS interfaces defect density, varying thicknesses and doping concentrations of the layers (absorber, buffer, BSF) on open‐circuit voltage (Voc), short‐circuit density (Jsc), fill factor (FF), and power conversion efficiency. Findings illustrate that the highest conversion efficiency of the Zn (O, S)/CZTS solar cell reached 14.65% with Voc = 0.9972 V, Jsc = 18.37 mA cm−2 and FF = 79.96% which is better than the CdS/CZTS structure. [ABSTRACT FROM AUTHOR]

This unique research investigates the co-doping effects of Ba and Ra on the structural, electronic, optical, thermodynamics and mechanical response of Bulk-like ZnO and ZnS based 3d-dimensional crystal structures. Using Heyd-Scuseria-Ernzerhof screened hybrid functional (HSE06) and generalized gradient approximation with norm-converging pseudopotential approach in the density functional theory. The (Ba, Ra)-doped ZnO (BZO, RZO) and (Ba, Ra)-doped ZnS (BZS, RZS) models with doping concentrations are assembled to systematically declare the impact of doping concentration (x) on the optoelectronic performance of ZnO and ZnS. Additionally, optoelectronic excellency, such as band gap tuning, electronic conductivity, reflectivity, transmittance and absorption as well as mechanical stability have been computed. It is observed that after (Ba, Ra)-doping and its impact on crystal vacancy can influence band levels hence decreasing the band gap of the 3d ZnO and ZnS. As a consequence, the decreased band gap is attributed to the enhanced absorption in the visible region and explores wide the applicable range of ZnS and ZnO. Compared to the ZnO, it is revealed that (BZO RZO) and (BZS, RZS) are remarkably much softer with 18% stiffness and 33% ultimate strengths computed respectively. The excess specific heat (CV) and enthalpy of mixing (Hm) as well as phonon responses resulting from the concentration x are estimated to investigate the thermodynamic stability responses of the Zn0.97Ba0.03O, Zn0.97Ra0.03O and Zn0.97Ba0.03S, Zn0.97Ra0.03S. Finally, the absorption and conductivity as well as optical performance of BZO, RZO and BZS, RZS materials are found to be extremely sensitive to the dopant concentrations. The obtained theoretical results indicate that the doped BZO, RZO and BZS, RZS materials can be proven as potential promising candidates for optoelectronic applications. [ABSTRACT FROM AUTHOR]

In the present work, we report acoustic shock wave recovery experimental findings on cubic zinc sulfide nanoparticles (ZnS NPs) with crystallographic, electronic and magnetic phase stability. The acquired X-ray diffraction (XRD) and magnetic results show that the ZnS NPs have a stable cubic crystalline structure, and however, owing to the reduction in defects, they result in reversible magnetic phase transitions from the weak-ferromagnetic to mixed-diamagnetic/ferromagnetic states at the corresponding 50 and 150 shocked conditions. The values of saturation magnetization are determined as 0.249, 0.052, 0.249 and 0.049 emu/g for 0, 50, 100 and 150 shocked conditions, respectively. Accordingly, the magnitude of the calculated band gap energies for 0, 50, 100 and 150 shocked conditions are identified to be 3.70, 3.85, 3.69, and 3.85 eV, respectively. Furthermore, the double peaks at corresponding positions of 161.67 (S 2p 3/2) and 162.97 (S 2p 1/2) of the X-ray photoelectron spectroscopy (XPS) are converted into the singlet peak at 162.23 (S 2p 1/2), demonstrating the reduction of the defect density at the 50-shocked condition. Finally, the structure-property relationship of cubic ZnS NPs and magnetic properties with respect to the exposed shocks are discussed in detail. Due to the switchable optical and magnetic properties by the number of shock pulses, cubic zinc sulfide nanoparticles can be suitable for spintronics devices and magnetically switchable applications. [ABSTRACT FROM AUTHOR]

For use in gas sensor packages, zinc sulfide (ZnS) thin films have been created utilizing the sol-gel dipping deposition process with copper (Cu) doping. Nitrogen dioxide (NO2) and hydrogen sulfate (H2S) are the measurement's goal gases. The probability of Cu doping was 1, 3 and 5 wt%. For morphological, structural, and microstructural characterization, Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD), and UV-visible measurements were used to determine optical properties. The presence of a hexagonal phase was shown by XRD patterns. Due to the more microstrain that brought about copper incorporation, with growing copper inclusion in ZnS thin films, there was a constant decline in particle length. The size variety of the produced hexagonal ZnS crystals turned into 9-17 nm, with a median length of approximately 12 nm. The band hole of the films fell from 3.2 eV for ZnS to 2.8 eV for 5% Cu-doped ZnS film, which could be because copper inclusion ended in an extra organized hexagonal shape. According to the outcomes of sensing homes, ZnS: 3%Cu film for NO2 gas at 150 °C and ZnS: 5%Cu for H2S gas at 250 °C had the best sensitivity. [ABSTRACT FROM AUTHOR]

Abstract The quest for mechanoluminescence (ML) in zinc sulfide (ZnS) spans more than a century, initially sparked by observations of natural minerals. There has been a resurgence in research into ML materials in recent decades, driven by advances in optoelectronic technologies and a deeper understanding of their luminescent properties under mechanical stress. ZnS, in particular, has garnered attention owing to its remarkable ability to sustain luminescence after more than 100,000 mechanical stimulations, positioning it as a standout candidate for optoelectronic applications. In contrast to conventional photoluminescent and electroluminescent light sources, ZnS composite elastomers have emerged as flexible, stretchable self‐powered light sources with considerable practical implications. This review introduces the development history, ML mechanisms, prototype ML devices, ZnS‐based ML material preparation methods, and their diverse applications spanning environmental mechanical‐to‐optical energy conversion, E‐signatures, anti‐counterfeiting, wearable information sensing devices, advanced battery‐free displays, biomedical imaging, and optical fiber sensors for human–computer interactions, among others. By integrating insights from ML‐optics, mechanics, and flexible optoelectronics, and by summarizing pertinent perspectives on current scientific challenges, application technology hurdles, and potential solutions for emerging scientific frontiers, this review aims to furnish fundamental guidance and conceptual frameworks for the design, advancement, and cutting‐edge application of novel mechanoluminescent materials.

The zinc smelting industry is a major source of atmospheric mercury emissions in China. It is crucial to develop a low-cost technology to reduce mercury pollution emissions for the green development of zinc smelting. Thus, based on the concept of “using waste to treat waste”, this study uses high-sulfur slag and secondary zinc oxide, which are produced in the zinc smelting process as raw materials, to prepare zinc sulfide adsorbent by high-temperature sulfurization in an inert atmosphere. The zinc sulfide adsorbents prepared under different roasting temperatures and time were characterized and analyzed by various analysis methods, including X-ray diffraction (XRD), Raman spectroscopy (Raman), scanning electron microscopy (SEM) and specific surface area analysis (BET). The effects of various reaction times and flue gas components on the mercury removal performance were studied. The experimental results reveal that the zinc sulfide adsorbent can be successfully prepared when the roasting temperature and holding time are more than 250 ℃ and 60 min, respectively. Under this condition, many mesoporous holes are formed. The prepared ZnS–250 ℃–90 min adsorbent has the best performance for Hg0 adsorption. Moreover, gaseous elemental mercury (Hg0) has an average adsorption efficiency above 98% at flue gas temperatures below 150 ℃, and it exhibits high resistance to O2, SO2, and H2O. When the Hg0 adsorption efficiency decreased to 50%, the Hg0 adsorption capacity of ZnS–250 ℃–90 min was 3.04 mg·g−1 in the simulated zinc smelting flue gas atmosphere, which is superior to conventional metal sulfides for Hg0 adsorption. Furthermore, the Hg0 adsorption on the surface of ZnS adsorbent is a chemical adsorption process, and the unsaturated short-chain sulfur on the surface of ZnS adsorbent is the critical active site, which can react with Hg0 to form stable HgS, thus realizing the high-efficiency purification of Hg0 from smelting flue gas. Furthermore, the spent ZnS adsorbent can be regenerated using thermal desorption and polysulfide impregnation. An excellent cycle performance for Hg0 capture is realized, and the Hg0 adsorption efficiency remains above 99% after five cycles. Simultaneously, the desorbed mercury can be recycled as elemental mercury by condensation during the regeneration process of ZnS adsorbent. Thus, this study not only provides a low-cost method for mercury pollution control and resource recovery from the zinc smelting industry but also supports the cyclic utilization of typical waste produced in the zinc smelting industry, promoting the green production of the zinc smelting industry.

Using the simple Chemical Bath Deposition (CBD) method, Cu-doped thin films of zinc sulfide (ZnS) were deposited on glass substrates in a concentration range of 0.05-0.1% Cu. These films were made to be used as a buffer or window layer in solar cells. Different deposition conditions were investigated to find the optimal growth conditions; after that, the conditions were deployed to deposit the required films. XRD graphs confirmed a hexagonal structure, and SEM images indicated that the incorporation of Cu stabilises small grain growth in the films. The appearance of the sample surface was dense, with an ordered granular shape, and free of any cracks. The optical and surface properties of the prepared films have been analysed using stateof-the-art instruments. The effect of pH on such properties has also been investigated. The transmittances of the films were about 20–85%, and the incident wavelength range was 300– 1100 nm. The transmission line shows a sharply increasing tendency. After that, it increases slowly and goes to a stable state above 400 nm. A film of pH 10.0 showed a high transmission coefficient (85%). Also, the absorbance of the ZnS thin films rapidly decreases up to 360 nm. After that, it decreases slowly and becomes stable above 400 nm. The band gap is in the range of 3.58–3.62 eV, which indicates that it absorbed the UV portion of the electromagnetic wave and could be used as the UV filter.

By exploiting the configuration of an alternate-current thin-film electroluminescent device, we observe the emission of light from a close-packed spin-cast layer of manganese-doped zinc sulfide nanoparticles (NPs), sandwiched between two dielectric layers, induced by the application of an AC voltage. By means of a microwave-assisted polyol synthesis, we are able to obtain high-crystalline surfactant-free NPs, which can be closely packed in the emitting layer, allowing an emission mechanism due to local charge creation and transport, instead of the typical impact-excitation process. This synthesis route allows us to get rid of a bulk semiconductor layer, implying that far less expensive routes for the active layer deposition such as spin coating, inkjet printing, or spray coating can be used. Our work allows us to get a deeper insight into the role played by the NP structure on the charge-transfer mechanism behind light emission and paves the way to a new generation of non-toxic quantum-dot-based displays. [ABSTRACT FROM AUTHOR]

Structure and energetics of rare-earth (RE) defects and luminescence of RE and related defects in zincblende zinc sulfide (ZnS) are investigated using hybrid density-functional defect calculations. We find that europium (Eu) is stable predominantly as the divalent Eu 2 + ion in bulk ZnS. The trivalent Eu 3 + ion is structurally and electronically stable but energetically unfavorable compared to Eu 2 + due to the presence of low-energy native defects and Eu 2 + -related defect complexes. Other RE dopants, dysprosium (Dy) and erbium (Er), are stable only as Dy 3 + and Er 3 + , respectively. These results provide an explanation why it is difficult to realize Eu 3 + in bulk ZnS. A non-negligible Eu 3 + /Eu 2 + ratio might be achieved with Li co-doping under S-rich (and probably non-equilibrium) synthesis conditions. Optically, Eu-related defects can act as carrier traps for band-to-defect transitions and emit light in the visible range. To assist with experimental optical characterization of the RE defects, we include band-to-defect luminescence involving native defects (Zn vacancies) and/or non-RE impurities (Cu, Cl, and Al) that may also be present in Eu-doped ZnS samples and assign luminescence centers often observed in experiments to specific defect configurations. [ABSTRACT FROM AUTHOR]

InP/ZnSe/ZnS quantum dots (QDs) stand as promising candidates for advancing QD-organic light-emitting diodes (QLED), but low emission efficiency due to their susceptibility to oxidation impedes applications. Structural defects play important roles in the emission efficiency degradation of QDs, but the formation mechanism of defects in oxidized QDs has been less investigated. Here, we investigated the impact of diverse structural defects formation on individual QDs and propagation during UV-facilitated oxidation using high-resolution (scanning) transmission electron microscopy. UV-facilitated oxidation of the QDs alters shell morphology by the formation of surface oxides, leaving ZnSe surfaces poorly passivated. Further oxidation leads to the formation of structural defects, such as dislocations, and induces strain at the oxide-QD interfaces, facilitating In diffusion from the QD core. These changes in the QD structures result in emission quenching. This study provides insight into the formation of structural defects through photo-oxidation, and their effects on emission properties of QDs. InP/ZnSe/ZnS quantum dots (QDs) are promising candidates for advanced light-emitting diodes, but low emission efficiency due to oxidation hampers applications. Here, the authors provide insight into the structural defects that form on individual QDs during UV-facilitated oxidation. [ABSTRACT FROM AUTHOR]