Chemical Bath Research Articles

Effect of chemical bath deposited V2O5 on TiO2 nanotubes for supercapacitor application

Effect of chemical bath deposited V2O5 on TiO2 nanotubes for supercapacitor application

The effect of deposition time on the morphology of CuS electrodes fabricated by chemical bath deposition for supercapacitor applications

The effect of deposition time on the morphology of CuS electrodes fabricated by chemical bath deposition for supercapacitor applications

Investigating the enhanced UV photoresponse of Cu-doped ZnO thin films synthesized via laser assisted chemical bath growth

Investigating the enhanced UV photoresponse of Cu-doped ZnO thin films synthesized via laser assisted chemical bath growth

Chemical Bath Deposition of NiFe Alloy Anode for Efficient Alkaline Water Electrolyzer Integration.

Green hydrogen production from water splitting is a feasible way for intermittent renewable energy storage and utilization, where the exploration and scale-up preparation of high-performance anodic oxygen evolution electrocatalysts are critical prerequisites for its industrial-level applications. Herein, a chemical bath deposition of FeNi3 intermetallic alloys onto Ni mesh support is performed, which delivers a current density of 0.62 Acm-2 at 1.72 V versus reversible hydrogen electrode for alkaline water oxidation in 1 m KOH and an excellent electrolysis stability at 0.2 A cm-2 for over 300 h. Moreover, via 3D computational fluid dynamics simulation and flow field optimization, a homogeneous deposition of ≈5400 cm2 NiFe anode is demonstrated within 4 min using the developed flow bath reactor. Once integrating the as-prepared NiFe anodes into alkaline electrolyzer stack, the voltage variation between each unit cell is below 40 mV at a total operation current of 71 A, or ca. current density of 0.2 A cm-2, confirming the uniformity of this batch synthesis protocol and its great potential for industrial alkaline water electrolysis.

Impact of layer thickness on the efficiency of solar cells designed with zinc-based thin films produced by chemical bath deposition

Impact of layer thickness on the efficiency of solar cells designed with zinc-based thin films produced by chemical bath deposition

Gas-sensitive synergistic effect of Au-decorated ZnO nano-structured materials for rapid ethanol detection based on simulated sunlight activation

Local surface plasmon resonance (LSPR) and noble metal modification/doping are classical methods for improving the performance of metal-oxide-semiconductor (MOS)-based gas sensors. However, relatively less attention is paid to their synergies. In particular, research on synergistic gas-sensing technology that combines sunlight activation with other methods is significant for using friendly energy. In this study, Au-decorated ZnO (Au/ZnO) nano-structured materials (NMs) are successfully synthesised using a cost-effective nano-seed-assisted chemical bath and UV irradiation growth methods. The sensor based on this material exhibits superior performance in ethanol vapour under simulated sunlight, maintaining high sensitivity and repeatability at a low optimal working temperature. In particular, the sensitivity to 100 ppm of ethanol is 7.5 times better and the response time is 20 times shorter (tres < 1 s) in simulated sunlight than in the dark environment. The limit of detection (LOD) of ethanol is as low as 97 ppb, which is much lower than the concentration in exhaled breath of driving under the influence of alcohol according to Chinese law (20–80 ppm). This study provides a reliable and ultra-fast ethanol detection method, with potential applications in environmental monitoring and traffic safety. A possible gas-sensitive mechanism of the Au/ZnO ethanol vapour sensor is proposed based on the synergistic effect between simulated sunlight activation (LSPR, humidity resistance and thermal activation) and noble metal modification (electron sensitisation and chemical sensitisation). It provides a promising method for exploring the utilisation of sunlight for rapid gas detection.

Influence of Zinc Ion Concentration on the Structural, Surface Morphology and Optical Properties of Zinc Selenide Thin Films

ZnSe thin films were deposited on nonconducting glass substrates using different Zn[Formula: see text] ion concentrations. The films were deposited at 80[Formula: see text]C for 2.0[Formula: see text]h via photo-assisted chemical bath technique and annealed for 2.0[Formula: see text]h at 250[Formula: see text]C. X-ray diffraction revealed a hexagonal structure with preferred orientation along the (002) plane and the average crystallite size decreased from 10.5[Formula: see text]nm to 6.8[Formula: see text]nm with increased Zn[Formula: see text] ions. Raman spectra were used to confirm ZnSe phonon modes whose intensity increased with Zn[Formula: see text] ion concentrations although with fluctuation. Optical analysis showed higher absorbance and low transmittance in the visible region than near infrared making the thin films good materials for selective absorber surfaces. The band gap increased from 2.52[Formula: see text]eV to 2.78[Formula: see text]eV as the Zn[Formula: see text] ion concentration varied from 0.05% to 0.25%. The presence of the desired elements was confirmed by the EDS. Photoluminescence studies revealed three emission peaks which were all ascribed to defect state levels in ZnSe and all the samples emitted in reddish color according to CIE color chromaticity analysis. The selective absorption, wide band gap and broad emission properties suggest that the material is promising for optoelectronic applications.

Solar Cells: Applications and Current Opinion

Due to the manufacturing process, silicon-based solar cells have conquered the marketplace, but their cost is not economic. As a result, thin-film manufacturing was done with low-cost, appealing materials generated using less expensive, scalable, and manufacturable procedures. The motivation behind this work is to develop low-cost, high-efficiency solar cells using chemical and electrochemical techniques. Thin film solar cell structure could be presented as glass, Cu structure, CdS window material, TCO, and CdTe absorber material. The absorber and window materials include layers such as CdS and CdTe, while Cu and TCO are the back and front contacts. By using CSS and chemical bath deposition (CBD), The usual method of making this structure is to grow window (CdS) and absorber (CdTe) materials. CBD is a batch method that generates enormous quantities of Cd-containing waste solutions each time, adding to the production process's high cost. Sputtering or PVD, including high vacuum conditions, is performed with back and front contacts. This research program focuses on developing an "all chemical-solar cell" structure. This study showed that CdS and CdTe materials may be employed and electrodeposited in thin-film solar cell systems, CBD and electroless techniques. Furthermore, the back and front contacts can be coated using the CdS electrolytic bath, which is utilized for seven months without being discarded, but the CBD bath lasts 2-3 days. The deposition rate of the thin films was about 50 - 100 times greater than reported values in the literature. The efficiency of the manufactured cells was between 1 and 6%, which was reduced by the duration of time. Twenty days after manufacturing a TCO, CdS, CdTe, the short-circuit current, Cu-Ag solar cell, and open-circuit voltage deposited by all chemical and electrochemical deposition techniques were 0.8 mA/cm2 and 8.8 mV, respectively. However, consistency and reproducibility remain unresolved. The growth of CdTe nanocrystalline thin film is one of the reasons it has been identified as having nanosized tracks. High-quality CdTe layers should be developed, or in cadmium solar cells, its layered structure is the form of a cadmium window and a zinc oxide buffer layer to increase the consistency of the solar cell efficiency.

Enhanced Performance of Close-Spaced Sublimation Processed Antimony Sulfide Solar Cells via Seed-Mediated Growth.

Antimony sulfide (Sb2S3) has attracted much attention due to its great prospect to construct highly efficient, cost-effective, and environment-friendly solar cells. The scalable close-spaced sublimation (CSS) is a well-developed physical deposition method to fabricate thin films for photovoltaics. However, the CSS-processed absorber films typically involve small grain size with high-density grain boundaries (GBs), resulting in severe defects-induced charge-carrier nonradiative recombination and further large open-circuit voltage (VOC) losses. In this work, it is demonstrated that a chemical bath deposited-Sb2S3 seed layer can serve as crystal nuclei and mediate the growth of large-grained, highly compact CSS-processed Sb2S3 films. This seed-mediated Sb2S3 film affords reduced defect density and enhanced charge-carrier transport, which yields an improved power conversion efficiency (PCE) of 4.78% for planar Sb2S3 solar cells. Moreover, the VOC of 0.755V that is obtained is the highest reported thus far for vacuum-based evaporation and sublimation processed Sb2S3 devices. This work demonstrates an effective strategy to deposit high-quality low-defect-density Sb2S3 films via vacuum-based physical methods for optoelectronic applications.

Selenium‐Rich Sb2(S,Se)3 Thin Films Deposited via Sequential Chemical Bath Deposition for High‐Efficiency Solar Cells

AbstractRecently, solution‐processed antimony sulfoselenide (Sb2(S,Se)3) thin films and solar cells have gained popularity and achieved impressive results. One of the most effective improvements is the chemical bath deposition (CBD) approach, which is gentle, highly adjustable, and scalable. However, development in alloyed Sb2(S,Se)3 using this process has been modest, with a power conversion efficiency (PCE) of roughly 8%. In this work, a sequential CBD deposition strategy is designed, introducing sulfur (S) or selenium (Se) sources at different stages of the CBD process to achieve high‐quality Sb2(S,Se)3 thin films and devices. Impressively, adding a moderate amount of sodium thiosulfate and thioacetamide as mixed sulfur sources during the CBD deposition of Sb2Se3 can produce Se‐rich Sb2(S,Se)3 films with high crystallinity, suitable bandgaps, low defect density, and favorable energy level alignment. With a short‐circuit current density (JSC) of 26.80 mA cm−2 and a fill factor (FF) of 65.89%, the solar cells with the FTO/CdS/Sb2(S,Se)3/Spiro‐OMeTAD/Au structure obtained an impressive PCE of 9.29%, the highest to date for Sb2(S,Se)3 solar cells manufactured with the CBD process. This study provides a feasible approach for enhancing the performance of CBD‐produced Sb2(S,Se)3 solar cells and offers new insights and techniques for the synthesis of other complex multicomponent thin films.

Optimization of deposition time on structural, morphological, and optical properties of Cd1-xZnxS nanocrystalline thin films

In this work, Cd1-xZnxS nanocrystalline thin films have been synthesized over a glass substrate by a simple and cost-effective Chemical Bath Deposition (CBD) technique at various deposition time keeping other deposition parameters constant. The structural, morphological, and optical properties are studied by incorporating a range of characterization techniques, including X-ray diffraction (XRD), Field Emission Scanning Electron Microscopes (FESEM), Energy Dispersive X-rays (EDX), and UV–Visible spectrophotometers (UV–Vis). The films have been deposited at five different deposition time in the range from 30 mins to 150 mins to record the changes which address in depth the structural, morphological and optical properties. Empirical fitting equations have also been developed to obtain a more quantitative analysis of the effect of deposition time. The results obtained in this work are compared with some recent reported works for performance analysis of the buffer layer. The proposed buffer layer deposited at 30 mins not only attains all the desirable qualities required for maximum extraction of solar energy but also a low-cost and environment friendly option, making it a potential candidate for solar cell and optoelectronic applications.

The effect of selenium ions concentration on zinc selenide thin films prepared by photo-assisted chemical bath deposition method

The effect of selenium ions concentration on zinc selenide thin films prepared by photo-assisted chemical bath deposition method

Enhancement of carrier concentration in chemical bath deposited copper sulfide (CuxS) thin film by post-growth annealing treatment

Copper sulfide thin films (CuxS, 1 ≤ x ≤ 2), owing to their unique optical and electrical properties, have attracted enormous attention in recent research. As one of the chalcogenide semiconductors, CuxS is used in several applications such as chemical sensors, photo-absorbing layers, photovoltaics, and lithium-ion batteries. In this study, copper sulfide thin film (CuxS; where 1 ≤ x ≤ 2) has been deposited by the chemical bath deposition method (CBD) at 27 °C with the molar ratio for copper and sulfur as 1:5, respectively. The structural, compositional, morphological, optical, and electrical properties of as-deposited and annealed CuxS thin films are investigated. From XRD plots, the presence of a mixture of two co-existing polycrystalline phases is observed, i. e. covellite phase with CuS stoichiometry and digenite phase with Cu1.8S stoichiometry up to an annealing temperature of 200 °C. At higher annealing temperatures, i.e. at 300 °C and 400 °C, the phase of CuxS thin film gets completely converted to digenite phase with Cu1.8S stoichiometry and chalcocite phase with Cu2S stoichiometry respectively. There is an enhancement in the crystallinity of CuxS thin film with an increase in annealing temperature as confirmed by XRD and Raman results. The optical bandgap of CuxS thin film is found to be decreased from 2.81 eV to 1.66 eV with an increase in the annealing temperature. The CuxS thin films are found to be p-type in nature, and the film annealed at 400 °C possesses the highest carrier concentration as revealed from the Hall effect measurement. This study aims to investigate the improvement of electrical properties of CuxS thin film with the variation in annealing temperature for optoelectronic applications such as photodetector.

Aluminum doped zinc oxide as UV laser-based nanothermometer

Abstract This work explores thermal laser-based sensor capabilities utilising random lasing emission obtained from zinc oxide (ZnO) nanorods prepared by chemical bath deposition. The ZnO nanorods were doped with Aluminum (Al) at a concentration of 10 mM by using a simple dip method for several dip durations of 20 s, 30 s, 40 s, 60 s and 80 s, respectively. In our previous work, we successfully observed random lasing emission. Building on these findings, this work delves deeper into the thermal sensitivity of nanorod structure at room temperature within the ultraviolet (UV) range. The highest thermal sensitivity of 0.001 °C-1 was obtained from Al-doped ZnO nanorods that were dipped for 60 s. The lasing threshold was 22.92 mJ/cm2 and the lasing spectral width was 1.16 nm.

Low-cost fabrication methods of ZnO nanorods and their physical and photoelectrochemical properties for optoelectronic applications

Zinc Oxide (ZnO) nanorods have great potential in several applications including gas sensors, light-emitting diodes, and solar cells because of their unique properties. Here, three low cost and ecofriendly techniques were used to produce ZnO nanorods on FTO substrates: hydrothermal, chemical bath deposition (CBD), and electrochemical deposition (ECD). This study explores the impact of such methods on the optical, structural, electrical, morphological, and photoelectrochemical properties of nanorods using various measurements. XRD analysis confirmed the hexagonal wurtzite structure of ZnO nanorods in all three methods, with hydrothermal showing a preferred orientation (002) and CBD and ECD samples showing multiple growth directions, with average particle sizes of 31 nm, 34 nm, and 33 nm, respectively. Raman spectra revealed hexagonal Wurtzite structure of ZnO, with hydrothermal method exhibiting higher E2 (high) peak at 438 cm−1 than CBD and ECD methods. SEM results revealed hexagonal ZnO nanorods became more regular and thicker for the hydrothermal method, while CBD and ECD led to less uniform with voids. UV-vis spectra showed absorption lines between 390 nm and 360 nm. Optical bandgap energies were calculated as 3.32 eV, 3.22 eV, and 3.23 eV for hydrothermal, CBD, and ECD samples, respectively. PL spectra revealed UV emission band with a small intensity peak around 389 nm and visible emission peaks at 580 nm. Temperature dependent PL measurements for ZnO nanorods indicated that the intensities ratio between bound exciton and free exciton decreases with temperature increases for the three methods. Photocurrent measurements revealed ZnO nanorod films as n-type semiconductors, with photocurrent values of 2.25 µA, 0.28 µA, and 0.3 µA for hydrothermal, CBD, and ECD samples, and photosensitivity values of 8.01, 2.79, and 3.56 respectively. Our results suggest that the hydrothermal method is the most effective approach for fabricating high-quality ZnO nanorods for optoelectronic applications.

Design of type II quaternary double-decker heterostructure Cu-WO3-BiVO4-Bi2S3[sbnd]NiOOH photoanode for stable and efficient photoelectrochemical water splitting

BackgroundBismuth vanadate (BiVO4) and nickel oxyhydroxide (NiOOH) are the prominent photo(electro)catalysts for water-splitting photoelectrodes. The strong visible light absorbers of the Bi2S3 decorated type II photoanode of WO3/BiVO4/NiOOH efficiently improve the photo-excitons in the photoanodes. MethodsIn this work, type II semiconductors heterostructure photoanodes are fabricated as Cu:WO3/BiVO4/Bi2S3/NiOOH. The bottom layer of heavily Cu- doped n-type WO3 nanoplatelets is grown on FTO to make nano-heterostructure Cu:WO3/BiVO4 photoanodes. The Bi2S3 semiconductor has been grown on the BiVO4 by chemical bath deposition and NiOOH deposited using the photo-assisted electrodeposition method. The resulting periodically ordered BiVO4/WO3 platelets distinctly outperform by the Bi2S3 and NiOOH-decorated quaternary photoanodes. Significant findingsAs a result, the as-prepared photoanode shows a high photocurrent density of 6.85 mA cm−2 at 0 V vs. Ag/AgCl under the irradiation of 100 mW/cm2 AM 1.5 G simulated sunlight. With the higher photoactivity of Bi2S3 and NiOOH cocatalysts, the photoanode substantially gains stability at higher saturation photocurrents. Overall, the photoanode resulted in a low charge transfer resistance (387.4 Ohm.cm2) and a higher built-in potential of 180 mV, with 2.67 % of ABPE and 2.1 % of STH efficiencies at 0.3 V vs. Ag/AgCl.

CBD-synthesized Mg-doped CdS thin films for hybrid solar cells and self-powered photodetectors

Mg-doped CdS samples were deposited via chemical bath deposition onto fluorine-doped tin oxide slides with varying levels of Mg-doping. Structural analysis revealed improved crystal quality in CdS films upon Mg incorporation. Morphological examinations indicated a reduction in grain size alongside appearance of smooth, void-free surfaces particularly evident at 3 % Mg-doping. Mg-doping also resulted in enhanced transparency of CdS films, notably at 3 % and 5 % within the visible spectrum. Efficient exciton dissociation was observed in hybrid solar cells based on 1 % and 3 % Mg-doped CdS, as evidenced by photoluminescence. Top-performing solar cell achieved an efficiency of 0.220 %, nearly seven times that of control device. 5 % Mg-doped CdS-based photodetectors exhibited favorable photosensing characteristics: a responsivity of 0.011 A/W, detectivity of 4.4 × 108 Jones, external quantum efficiency of 3.1 %, and rise/decay times of 26/25 ms at zero bias. These findings underscore beneficial effects of Mg-doping on both hybrid solar cell and self-driven photodetector performance.

Enhanced UV photodetector using Mg-doped ZnO sub-micro tube films synthesized through laser-assisted chemical bath growth

This study presents the fabrication of MgxZn(100-X)O thin films (TFs) with Mg concentration levels (x) of 0.5 at%, 1.0 at%, 1.5 at%, and 2.0 at% on glass substrates using the novel laser-assisted chemical bath growth (LACBG) method, aimed at investigating their photo-response for potential UV photodetector applications. Utilizing a continuous wave semiconductor laser with a 444.5 nm wavelength, 1 W power, and 6 min of irradiation, the LACBG method successfully produced high-quality Mg-doped ZnO TFs. These films were deposited on glass substrates coated with silver (Ag) to serve as electrode contacts for constructing a metal-semiconductor-metal (MSM) UV photodetector. The structural, optical, and electrical properties of the TFs were thoroughly analyzed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to examine the crystal microstructures and surface morphologies, revealing vertically aligned hexagonal symmetrical sub-micro tubes. In contrast, energy dispersive X-ray (EDX) analysis confirmed successful Mg incorporation into the ZnO lattice. UV–visible absorbance spectra indicated a blue shift in the absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with rising Mg content. The UV photodetectors, particularly those with 2.0 at% Mg-doped ZnO TFs, demonstrated significantly enhanced UV responsiveness attributed to optical confinement, high surface-to-volume ratio, and superior structural quality. Performance metrics for the 2.0 at% Mg-doped ZnO TFs included a responsivity of 10.60 A/W, external quantum efficiency of 34.10, specific detectivity of 2.25 × 107 Jones, noise equivalent power of 5.34 × 10−11 W, rise time of 86.9 ms, and decay time of 324.4 ms. These findings underscore the potential of Mg-doped ZnO TFs for high-performance UV photodetection applications. The novelty of this study lies in utilizing LACBG to achieve high-quality Mg-doped ZnO TFs, offering a cost-effective, low-temperature method that enhances UV photodetector performance.

Synthesis and design strategies of codoped titanium dioxide with band alignment and multiple reflections of incident light for efficient visible light activity

To increase the visible-light photocatalytic performance of Titania, it was codoped with specific elements and was effectively synthesized. The goal of enhancing visible-light photocatalytic performance was achieved by broadening its absorption spectrum in the visible light range and enhancing the quantum efficiency of the photocatalytic reaction toward the degradation of the hazardous dye methyl orange. Mixed phase photocatalyst with different percentage hierarchical secondary nanostructure has been synthesized by the combination of chemical bath deposition methods and hydrothermal. The density of the sprout-like branches changes from the concentration levels of titanium butoxide in the precursor solution. Based on the experimental analysis, a mechanism was proposed to interpret the evolution of the secondary growth. The band edge difference between anatase and TiO2(B) phases induces transfer of charge at the interface. The result revealed that in the TiO2 crystal some O-sites were substituted by N and S anions resulting in band mixing and incorporation of extra energy states in between the valence band maxima and conduction band minimum, which caused a shift towards longer wavelengths in the absorption edge. Compared with pure TiO2 nanobelt, the surface modified doped samples exhibited good visible light activity. The combined effect of fast charge transfer in the atomic level contact between two phases and localized N 2p and S 3p band above valence-band edge in the same material makes titanium dioxide suitable for use in the presence of visible light.

Synthesis and properties of flexible supercapacitor based on zinc-aluminum layered doubled hydroxide

A flexible, effective supercapacitor using zinc-aluminum-layered double hydroxides (Zn-Al LDHs) as an electrode material is reported. Nanosheets of Zn-Al LDHs were synthesized using a chemical bath deposition method, and they were present in a well-standing shape covering the complete area of the Al foil. The imaging of these nanosheets showed that their average thickness is between 60 and 80 nm, with a width and length average of 1.3 and 0.6 μm, respectively. These dimensions help to create the connection arrangements of sheets with a high specific surface area of 88 m2/g which increased electrochemical active sites for charge storage. The X-ray diffraction further approves the structural properties of the prepared material. The flexibility of the supercapacitor was examined by bending and folding up the device to 180° with little mechanical deformation. The highest capacitance value is found to be ∼597F/g in the case of the flat condition. The capacitance value decreased to ∼387F/g after folding the device 30°, and these values drooped slightly after more increasing the folding angle. The energy density (ED) remains nearly constant at any folding angle (ED=3.39Wh/kg at 30° and ED=3.7Wh/kg at 135°), and similarly, the power density (PD) remains nearly constant (PD=27 kW/kg at 30° and 135°). The aforementioned approves the flexibility of the Zn-Al LHD because it provides lifelong stability (87 % retaining after 2000 charge/discharge cycles) and stable efficiency after different bending and twisting conditions. The impedance measurements along with the obtained equivalent circuits confirm the electrical characteristics of the as-prepared electrodes with low equivalent series resistances, ensuing the promising conductive path in the supercapacitor device.