- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Structural and optical studies on PVA capped SnS films grown by chemical bath deposition for solar cell application
摘要： Tin monosulphide (SnS) thin films capped by PVA have been successfully deposited on glass substrates for cost effective photovoltaic device applications by a simple and low-cost wet chemical process, chemical bath deposition (CBD) at different bath temperatures varying in the range, 50–80 °C. X–ray diffraction analysis showed that the deposited films were polycrystalline in nature, showing orthorhombic structure with an intense peak corresponding to (040) plane of SnS. These observations were further confirmed by Raman analysis. FTIR spectra showed the absorption bands which corresponds to PVA in addition to SnS. The scanning electron microscopy and atomic force microscopy studies revealed that the deposited SnS films were uniform and nanostructured with an average particle size of 4.9 to 7.6 nm. The optical investigations showed that the layers were highly absorbing with the optical absorption coefficient ~105 cm–1. A decrease in optical band gap from 1.92 to 1.55 eV with an increase of bath temperature was observed. The observed band gap values were higher than the bulk value of 1.3 eV, which might be due to quantum confinement effect. The optical band gap values were also used to calculate particle size and the results are discussed.
关键词： structural properties,optical properties,SnS thin films,polyvinyl alcohol,capping agent,chemical bath deposition
更新于2025-11-21 11:18:25
-
Low-temperature synthesis and characterisation of its photocatalytic properties of BiNbO<SUB align="right">4 by combustion method using polyvinyl alcohol
摘要： BiNbO4 nanopowders were synthesised by polyvinyl alcohol sol-gel combustion method using freshly starting material Nb2O5. nH2O. The prepared samples were characterised by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and thermal gravimetric and differential thermal analysis. The orthorhombic single phase calcined at 750°C for 2 h in the air was thoroughly studied with the highest photocatalytic properties in 25 nm average size. Methyl orange was used to evaluate the photocatalytic properties of BiNbO4 under the visible light irradiation which was degraded by 98%. The regeneration ability of the catalyst was reduced by only 1.65% from 98.85% to 97.20% after using four-times without recovery.
关键词： polyvinyl alcohol,BiNbO4 nanopowders,methylene orange degradation,combustion method
更新于2025-09-19 17:15:36
-
Biocompatible microlasers based on polyvinyl alcohol microspheres
摘要： Biocompatible microlasers, generally made of bio-derived materials, are promising for biosensing and cell-tracking. These kinds of lasers offer favourable opportunities like biocompatibility and biodegradability but the materials used often require complicated synthesis and high cost. In this work, we demonstrate that polyvinyl alcohol (PVA), a synthetic water-soluble low-cost polymer, with fascinating properties such as good transparency, biocompatibility, biodegradability is an excellent candidate for making laser cavity. Using a simple and effective technique, dye-doped PVA microspheres can be fabricated with various sizes from 10 to 200 μm. These microspheres can act as excellent lasers under optical excitation with a lasing threshold of ~2 μJ/mm2 and Q factor of lasing modes of ~3000. The lasing mechanism is studied and it is ascribed to WGM. Size-dependent lasing characteristics including lasing spectrum, Q factor and lasing threshold are investigated. Owing to the ease of fabrication, the cost-effectiveness, the biocompatibility of the PVA material, our biocompatible microlasers are promising for future biosensing applications.
关键词： Whispering gallery mode,Microlaser,Polyvinyl alcohol,Biocompatible
更新于2025-09-16 10:30:52
-
Tailoring optical transmittance of polyvinyl alcohol by FeCl3-doping for photovoltaic application
摘要： In this paper, solid ?lms of polyvinyl alcohol (PVA) complexed with di?erent concentration of FeCl3 have been successfully synthesized. X-ray di?raction showed that a drop in the crystallinity of PVA with FeCl3. UV-Vis spectra show that FeCl3 remarkably enhances UV absorption of PVA, indicating a reduction of optical band gap (OBG). This led to the assumption that increased UV absorption can be assigned to an in?uence of FeCl3 on PVA synthesis. In addition, OBG study shows decrements in the values of direct band gap and indirect band gap with FeCl3 content. These results led to conclude that FeCl3 doped PVA ?lms are good candidates in the packaging community and photovoltaic application.
关键词： photovoltaic application,optical transmittance,polyvinyl alcohol,FeCl3
更新于2025-09-16 10:30:52
-
Synthesis of ZnO nanoparticles in polyvinyl alcohol solutions using laser assisted synthesis in solution (LASiS) method
摘要： ZnO nanoparticles are widely studied because of their superior properties so they are widely used in various applications. Structural modification with the right synthesis method is the key to getting superior properties. In this experiment, Laser Assisted Synthesis in Solution (LASiS) method was used to synthesize ZnO nanoparticles. The LASIS method was carried out using a metal plate Zn as a target placed in a solution of polyvinyl alcohol (PVA) with different concentrations, namely 1%, 2%, 3% and 4%. This laser ablation has caused a solution of gray colloidal ZnO nanoparticles. Different PVA concentrations do not affect the color of the produced ZnO nanoparticle solution. The properties and structure of ZnO nanoparticles were characterized using UV-Vis spectrophotometer, Zetasizer spectrometer, and Transmission Electron Microscopy (TEM). The UV visible absorbance spectrum shows the maximum absorption characteristics of ZnO nanoparticles observed at a wavelength of 344 nm. The maximum absorbance value rises by increasing the concentration of PVA and reaching the maximum value at a concentration of 3%. These ZnO nanoparticles have a size around 80 nm. TEM analysis shows that ZnO nanoparticles have a spherical shape and have good crystallinity based on SAED measurements. This property is due to the role of PVA in the synthesis process.
关键词： ZnO nanoparticles,polyvinyl alcohol,UV-Vis spectrophotometer,Zetasizer spectrometer,LASiS method,Transmission Electron Microscopy
更新于2025-09-12 10:27:22
-
Preparation of TiO2 compact layer by heat treatment of electrospun TiO2 composite for dye-sensitized solar cells
摘要： The power conversion efficiency (PCE) of the dye-sensitized solar cell was improved by using titanium dioxide (TiO2) compact layer prepared via heat treatment assisted electrospinning. Titanium tetraisopropoxide mixed with polyvinyl-alcohol was used as the electrospun solution. In this study, TiO2 photoanode with TiO2 compact layer was compared with TiO2 photoanode without TiO2 compact layer where the PCE was improved by 76.88%. Electrochemical impedance spectroscopy proved that the TiO2 compact layer can reduce the series resistance and improved the short circuit current density, resulting in a low recombination effect that leads to a higher PCE. The electron lifetime and charge collection efficiency of TiO2 nanoparticles with TiO2 compact layer displayed a higher value compared to TiO2 nanoparticles without TiO2 compact layer.
关键词： titanium isopropoxide,polyvinyl alcohol,dye-sensitized solar cell,compact layer,electrospinning
更新于2025-09-11 14:15:04
-
Modulating chain conformations of polyvinyl alcohol through low cost and nontoxic glyoxal crosslinker: Application in high performance organic transistors
摘要： High leakage current and presence of numerous polar hydroxyl groups have often appeared as severe performance obstacles for polyvinyl alcohol (PVA) on its application in organic ?eld e?ect transistor devices. Herein, we report a facile, yet e?cient functionalization and chain structure modi?cation technique to enhance its e?cacy as a gate insulating layer. In this work, we have used glyoxal as a cross-linking agent of PVA to modulate its chain conformation and performed a detailed analysis to explore the role of glyoxal crosslinking on the electrical and structural properties of PVA. Applying various amount of glyoxal solution we have properly optimized the dose of the crosslinker to be used in the crosslinking reaction so that minimum amount of leakage can be achieved. Substantial improvement in the insulation properties as well as surface characteristics was observed after the structural modi?cation of the polymer. Correspondingly, organic FETs were fabricated using crosslinked PVA to gauge the e?ect of crosslinking on the device performance of the transistors. Post-crosslinking improvements in the polymer bulk and surface characteristics were clearly emulated in the device performance parameters. Field-e?ect mobility as high as 5.4 cm2/V-s and 1.7 cm2/V-s were achieved employing crosslinked PVA as gate dielectric layer in Dinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (DNTT) and pentacene based devices, respectively. Thus, our study illustrates the viability of crosslinking PVA using glyoxal and hence, can catalyze the limited use of PVA in electronic applications.
关键词： Crosslinking,Organic ?eld e?ect transistor,Gate dielectric,Polyvinyl alcohol,Glyoxal
更新于2025-09-10 09:29:36
-
AIP Conference Proceedings [Author(s) 6TH INTERNATIONAL CONFERENCE ON PRODUCTION, ENERGY AND RELIABILITY 2018: World Engineering Science & Technology Congress (ESTCON) - Kuala Lumpur, Malaysia (13–14 August 2018)] - Investigation of optical and electrical properties of nitrogen- and boron-doped carbon dots films
摘要： The optical properties of two types of carbon dots (CDs) doped by nitrogen and boron atoms and the electrical properties of ?lms from the obtained CDs in a polyvinyl alcohol (PVA) matrix were investigated. Synthesis of CDs was carried out using the hydrothermal treatment method. The resulting CDs have a crystalline structure with functional groups on the edges and surface (lateral sizes of CDs is vary in the range of ～7 ?28 nm). The thin ?lms from aqueous suspensions of CDs were obtained by the spin-coating method inside an electrically inert polymer matrix of PVA. The current-voltage characteristics of this obtained ?lms were measured.
关键词： optical properties,polyvinyl alcohol matrix,current-voltage characteristics,carbon dots,electrical properties,spin-coating method,hydrothermal treatment,nitrogen-doped,boron-doped
更新于2025-09-09 09:28:46
-
[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Flexible High Magnetodielectric Materials for Antenna Applications (Invited)
摘要： A novel flexible magneto-dielectric (MD) substrate with high permeability (μr) and permittivity (εr) is developed in this work, and the excellent capability of the novel material for realizing miniaturized and broadband flexible antenna is demonstrated. The MD substrate is mainly comprised of NiZnCo ferrite and polyvinyl alcohol (PVA) through extrusion technology and obtains relatively high μr around 4.5 and εr around 9.0 over a wide frequency range of 10 MHz–1 GHz. A benchmark structure of square microstrip patch antenna was simulated using the common polyimide (PI) flexible substrate and the developed MD substrate, respectively, and MD substrate proves remarkable miniaturization effect. Based on the developed MD substrate, a miniaturized patch antenna working at ultrahigh frequency (UHF) 915 MHz was designed. The overall size of the antenna is 40×40×1 mm3, which is only one-quarter size of the PI substrate antenna. Also, the impedance bandwidth (S11<-10 dB) is enhanced from 8 MHz (910–918 MHz) to 30 MHz (900–930 MHz) for the MD substrate antenna.
关键词： flexible magneto-dielectric substrate,broadband antenna,polyvinyl alcohol,miniaturized antenna,NiZnCo ferrite
更新于2025-09-04 15:30:14