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Liquefied petroleum gas sensing properties of ZnO/PPy/PbS QDs nanocomposite prepared by self-assembly combining with SILAR method
摘要： In this paper, a high-performance liquefied petroleum gas (LPG) sensor based on zinc oxide/polypyrrole/lead sulfide quantum dots (ZnO/PPy/PbS QDs) nanocomposite film was demonstrated, which was fabricated by layer-by-layer (LbL) self-assembly and successive ionic layer adsorption and reaction (SILAR) technique. The nanostructure features of the as-prepared ZnO/PPy/PbS nanocomposite film were confirmed by various characterization techniques. The room temperature gas-sensing investigation of the ZnO/PPy/PbS QDs nanocomposite sensor was performed against LPG gas in a wide concentration range. The experimental results showed an outstanding response for LPG sensing at room temperature compared with previous reports, the response can reach 45.47% at 1000 ppm LPG. And it also demonstrated good selectivity and excellent repeatability. The sensing mechanism of the PPy/ZnO/PbS QDs nanocomposite film gas sensor is owing to the p-n heterojunction created at the ZnO/PPy interface, as well as much more active adsorption sites.
关键词： polypyrrole,liquefied petroleum gas,zinc oxide,lead sulfide quantum dots,SILAR method
更新于2025-11-14 17:04:02
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Complexing agent triethanolamine mediated synthesis of nanocrystalline CuO thin films at room temperature via SILAR technique
摘要： In the present work, nanostructured cupric oxide (CuO) thin films have been successfully deposited on glass substrates by successive ionic layer adsorption and reaction (SILAR) technique at room temperature. The influence of complexing agent as triethanolamine (TEA) on the structural, morphological, optical and electrical characteristics of nanocrystalline CuO thin films have been examined in detail. Structural studies confirm that all the films were polycrystalline nature having a monoclinic crystalline form and displayed (111) and (111) preferential orientations. The estimated crystallite values ranged from 17.47 to 19.95 nm. The surface morphology of CuO thin films was examined through scanning electron microscopy and materials microscope studies. Surface studies revealed that homogeneously distributed CuO nanostructures on the film surfaces. The optical studies showed that band gap energy values of the CuO thin films were increased from 1.33 to 2.00 eV as a function of increasing TEA concentration. Meanwhile, the average transmittance of all the films had increased from 2.5 to 42.5% with the increasing TEA concentration. FTIR studies identified the formation of single phase CuO and chemical bonding of the complexing agent. The resistivity value of CuO thin film synthesized without TEA was 3.74 × 10^5 Ω.cm and the resistivity consequently increased to 509 × 10^5 Ω.cm with TEA concentration of 1.0 M%. A high figure of merit (786×10^{-12} Ω^{-1}) was obtained for complexing agent concentration of 0.25 M%.
关键词： SILAR,Surfactant,TEA,CuO thin film
更新于2025-10-24 16:32:58
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Nanostructured ZnO sensor fabricated by successive ionic layer adsorption and reaction method for ammonia sensing application
摘要： ZnO thin films were deposited onto glass substrate for various deposition cycles by successive ionic layer adsorption and reaction method. Structural studies were confirmed that the films are polycrystalline with hexagonal wurtzite structure. SEM studies revealed the surface had closely packed spherical particles with pores. The transmission range was found to be above 75% and the band gap was calculated for all samples using optical studies. The changes in the oxidation state of ZnO thin film was studied using X-ray photoelectron spectroscopy. The chemical compositions of ZnO were confirmed by FTIR spectrum. The improved crystalline of ZnO thin film (50 cycles) has been chosen for the fabrication of ammonia vapour sensor. The vapour sensing behaviour of the film was observed for various concentrations of ammonia at an optimized operating temperature of 200oC. The lowest detection limit was found to be 1 ppm of ammonia vapour concentration.
关键词： Ammonia vapour,Sensing properties,SILAR,ZnO,topographical properties
更新于2025-09-23 15:22:29
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Electron Diffusion Length and Charge Separation Efficiency in Nanostructured Ternary Metal Vanadate Photoelectrodes
摘要： Ternary metal vanadates have recently emerged as promising photoelectrode materials for sunlight-driven water splitting. Here, we show that highly active nanostructured BiVO4 films can be deposited onto fluorine-doped tin oxide (FTO) substrates by a facile sequential dipping method known as successive ionic layer adsorption and reaction (SILAR). After annealing and deposition of a cobalt phosphate (Co-Pi) co-catalyst, the photoelectrodes produce anodic photocurrents (under 100 mW cm-2 broadband illumination, 1.23 V vs. RHE) in pH 7 phosphate buffer that are on par with the highest reported in the literature for similar materials. To gain insight into the reason for the good performance of the deposited films, and to identify factors limiting their performance, incident photon-to-electron conversion efficiency spectra have been analyzed using a simple diffusion–reaction model to quantify the electron diffusion length (Ln; the average distance travelled before recombination) and charge separation efficiency (ηsep) in the films. The results indicate that ηsep approaches unity at sufficiently positive applied potential but the photocurrent is limited by significant charge collection losses due to a short Ln relative to the film thickness. The Co-Pi catalyst is found to improve ηsep at low potentials as well as increase Ln at all potentials studied. These findings help to clarify the role of the Co-Pi co-catalyst and show that there could be room for improvement of BiVO4 photoanodes deposited by SILAR if Ln can be increased.
关键词： charge separation efficiency,ternary metal vanadates,SILAR,electron diffusion length
更新于2025-09-23 15:22:29
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AIP Conference Proceedings [Author(s) PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON CURRENT PROGRESS IN MATHEMATICS AND SCIENCES 2017 (ISCPMS2017) - Bali, Indonesia (26–27 July 2017)] - Nickel sulfide sensitized TiO2 nanotubes system as photo-anode: Will this system active under visible light and why?
摘要： This work is dedicated to enhance the photo catalytic activity of the modified 2 nanotube under visible light exposure. The narrow band gap of semiconductor such as NiS can be incorporated onto TiO2 nanotube (NiS/TiO2-NT) to obtain a composite which may active under visible light. The TiO2 nanotube was self-prepared by electro-oxidation of titanium plate in electrolyte containing ethylene glycol, NH4F, and water. Meanwhile, the incorporation of NiS onto TiO2 film was prepared by successive ionic layer absorption and reaction (SILAR) method, in which nickel(II) ion and sulfide ion were used as the precursor of NiS, to obtain the NiS/TiO2-NT film system. The obtained NiS/TiO2-NT films were characterized by UVDRS, FTIR, SEM, XRD, and photo-electro-chemical work station. The resultsindicated that the peak of absorption spectra of NiS/TiO2-NT fall within thevisible light region, which the final band gap was 2.85 eV; IR and XRD spectra were also revealed the characteristic peak of NiS/TiO2-NT system. Photo-electrochemical investigation revealed that the evolution of photocurrent under visible light (100 W wolfram lamp), as much as 0.26 mA/cm2 typically can be easily observed.
关键词： photo-electrode,SILAR,NiS/TiO2
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Room Temperature Processed Transparent Cu-Zn-S Nanocomposites as Hole Transport Materials in CdTe Photovoltaics
摘要： Here, we report room temperature processed Cu-Zn-S ternary thin films fabricated using SILAR method as a back-contact hole transport layer in cadmium telluride (CdTe) solar cells. These Cu-Zn-S films are transparent to visible region with compact grains, and high conductivity. X-ray diffraction (XRD) measurements shows the crystalline nature of the as-deposited Cu-Zn-S films. The Cu-Zn-S nanocomposite as a back contact buffer layer in CdTe devices improves the device performance to 12.7% (average 12.4%) from 10.4% (average 9.8%) compared to a Au only back contact and is comparable to Cu/Au back contact (thermally evaporated). The temperature dependence current voltage characteristics shows the reduced back barrier height compared to Au only and Cu/Au back contact.
关键词： SILAR,Cu-Zn-S,back contact,hole transport layer (HTL),solar cells
更新于2025-09-23 15:21:01
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Adsorption and Cation Exchange Behavior of Zinc Sulfide (ZnS) on Mesoporous TiO2 Film and Its Applications to Solar Cells
摘要： Zinc sulfide (ZnS) was deposited onto the surface of mesoporous TiO2 film by a typical successive ionic layer adsorption and reaction (SILAR) process. By inducing a spontaneous cation exchange between ZnS and a target cation (Pb2+, Cu2+, Ag+, or Bi3+) dissolved in chemical bath when they are in contact, it was demonstrated successfully that white translucent ZnS on the substrate could be changed to brown-colored new metal chalcogenides and the amount of ZnS deposited originally by different conditions could be compared in a qualitative way with the degree of the color change. By utilizing this simple but effective process, the evolution of well-known ZnS passivation layer prepared from different chemical baths in quantum dot (QD)-sensitized solar cells could be tracked visually via checking the degree of color change of TiO2/ZnS electrodes after the induced specific cation exchange. When applied to representative CdS QD-sensitized solar cells, it was revealed clearly how the different degree and rate of ZnS deposition could affect the overall power conversion efficiency while finding an optimized passivation layer over TiO2/CdS electrode. Acetate anion-coupled Zn2+ source was observed to give a much faster deposition of ZnS passivation layer than nitrate anion one due to its higher pH-induced more favorable adsorption of Zn2+ on the surface of TiO2. As another useful application of the ZnS-based cation exchange, as-deposited ZnS was used as a template for preparing a more complex metal chalcogenide onto mesoporous TiO2 film. The ZnS-derived Sb2S3-sensitized electrode showed a promising initial result of over 1.0 % overall power conversion efficiency with a very thin ZrO2 passivation layer between TiO2 and Sb2S3.
关键词： passivation,Quantum dot-sensitizer,SILAR deposition,zinc sulfide,solar cell,cation exchange
更新于2025-09-23 15:21:01
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Synthesis of SnSe quantum dots by successive ionic layer adsorption and reaction (SILAR) method for efficient solar cells applications
摘要： Quantum dots (QDs) are one of the promising materials in the development of third-generation photovoltaics. QDs have the advantage of multiple exciton generation (MEG), high absorption coefficient and tuneable bandgap, low cost and easy synthesis. The QDs act as analogues to dye molecules in QD sensitized solar cells (QDSSCs) when compared with traditional dye-sensitized solar cells (DSSCs). Extending the absorption range of quantum dots is one of potential solutions for enhancing photoconversion efficiencies. The sensitization of SnSe quantum dots on theTiO2 mesoporous layers is carried by a successive ionic layer adsorption and reaction (SILAR) method in a glove box. The advantages of SILAR method are a high loading rate and wide coverage of the TiO2 matrix by the quantum dots. The device has exhibited a photoconversion efficiency of 0.78% which is the known best among the SnSe quantum dot-based solar cells.
关键词： Solar cell,SILAR method,Photovoltaic efficiency,Sulphide-polysulphide,Light trapping,SnSe Quantum dots,QDSSC
更新于2025-09-23 15:19:57
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Multiple Energy Applications of Quantum-dot Sensitized TiO2/PbS/CdS and TiO2/CdS/PbS Hierarchical Nanocomposites Synthesized via p-SILAR Technique
摘要： Pseudo-successive ionic layer adsorption and reaction (p-SILAR) process was opted for deposition of PbS/CdS and CdS/PbS QDs on TiO2 to combine light absorbing tendency of PbS and CdS QDs which evolved significant photocatalytic behavior in TiO2 under visible light irradiation. It was shown that the resultant TiO2/PbS/CdS hierarchical nanocomposite exhibited better photo-electrochemical behavior than TiO2/CdS/PbS, ensuing ~42 % higher degradation of acid orange-56 than the latter and ~65 % higher than pristine TiO2. In addition, both nanocomposites resulted promising antibacterial activity against Escherichia coli (E. coli). Particularly TiO2/PbS/CdS showed much greater inhibition zone (~14 mm) than TiO2 (~8 mm).
关键词： Quantum-dots,p-SILAR,nanocomposites,electrochemical,photocatalysis,E. coli.
更新于2025-09-19 17:15:36
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The role of cobalt doping on the optical and morphological properties of Mn3O4 nanostructured thin films obtained by SILAR technique
摘要： Cobalt doped manganese oxide thin films (Mn3O4:Co) were successfully deposited on soda lime glass substrates using SILAR technique. Mn3O4:Co thin films were characterized using XRD, SEM, Uv-VIS and Raman spectroscopy. The XRD spectra showed that thin films had substantially Hausmannite crystal structure. The preferential orientation of the pure and 0.5 at.% Co doped manganese oxide thin films (Mn3O4) was (002), but with increasing Co doping, it was detected that this preferential orientation shift towards the (211) plane. The absorbance, transmittance and optical band gap of the Mn3O4:Co thin films were determined using Uv-Vis spectroscopy and these properties of the thin films differed considerably due to cobalt doping. The optical band gap of pure Mn3O4 thin films was 2.00 eV, but on the other hand, due to the Co doping this value increased before and then decreased slightly. Optical transmittance of Mn3O4:Co films increased from 60 % to 70 % with the effect of Co doping. A1g mode, which is the characteristic vibration peak of Mn3O4 films, was confirmed for pure and doped Mn3O4 thin films at a wavelength of 658 nm.
关键词： RAMAN,SILAR,semiconductors,doping effect,Hausmannite
更新于2025-09-19 17:15:36