Structural,Optical and Electrochromic Properties of WO3 Thin Films Prepared by Chemical Spray Pyrolysis Versus Spin Coating Technique

In this study,Tungsten Oxide(WO_3)thin films were prepared by Chemical Spray Pyrolysis(CSP)and Spin Coating(SC)techniques and it was investigated effects of technique and parameter on the films.WO_3 thin films were deposited on ITO(Indium Tin Oxide)coated glasses.The structural,optical and electrochromic properties of the WO_3 thin films were characterized by XRD,SEM,UV,and CV measurements.The sharpest(200)peak was observed in the XRD spectra and optical band gaps were calculated around 2.6～3.1 eVvia UV-Vis spectra for all of the samples.Micro fibrous reticulated surface(filamentous like)morphology for the films deposited by CSP technique and smooth surface morphology with high optical transmittance for the film deposited by SC Technique were obtained from SEM images.In addition to these results,it was revealed that all the samples exhibit good electrochromic performance.

Preparation of Nano-TiO₂Thin Film Using Spin Coating Method

This paper presented the preparation of TiO2 thin film on empty glass and Indium Tin Oxide (ITO) glass by spin coating method. Highly transparent titanium oxide thin films were obtained. The Optical absorption and transmission of the film prepared from both the synthesized and the commercially available TiO2 were measured by the UV-Visible Spectrophotometer. A sharp absorption edge of the TiO2 film was observed. The estimated energy band gap for the film of the commercially available sample was larger than that of the synthesized one.

Preparation of Se-based solar cell using spin-coating method in ambient condition

A new hybrid organic-inorganic structure of FTO/TiO2/Se/HTL/Au based selenium solar cell has been fabricated through a low-cost spin-coating process in air. In this process, selenium is completely dissolved in hydrazine, to fk）rm a homogeneous precursor solution. After spin-coating the precursor solution on the TiO2 substrates, following by sintering at 200 ℃ for 5rain, a uniform selenium film with crystalline grains is formed. The selenium based solar cell exhibits an efficiency of 1.23% under AM1.5 illumination （100 mW.cm-2）, short-circuit current density of 8 mA.cm 2, open-circuit voltage of 0.55 V, and fill factor of 0.37. Moreover, the device shows a stable ability with almost the same performance alter 60 days.

Spin coating of TPB film on acrylic substrate and measurement of its wavelength shifting efficiency

Scintillation light from a liquid noble gas during a neutrino or dark matter experiment lies typically within the vacuum ultraviolet region and might be strongly absorbed by surrounding materials such as light guides or photomultipliers.Tetraphenyl butadiene(TPB)is a fluorescent material,acts as a wavelength shifter,and can turn UV light into visible light at a peak wavelength of approximately 425 nm,enabling the light signals to be easily detected during physics studies.Compared with a traditional TPB coating method using vapor deposition,we propose an alternative technique applying a spin-coating procedure to facilitate the development of neutrino and dark matter detectors.This article introduces a method to fabricate a TPB film on an acrylic substrate by using a spincoating method,reports the measurements of the sample film thickness and roughness,demonstrates the reemission spectrum,and quantifies the wavelength shifting efficiency.

Effect of substrate curvature on thickness distribution of polydimethylsiloxane thin film in spin coating process

The polymer spin coating is critical in flexible electronic manufaction and micro-electro-mechanical system（MEMS）devices due to its simple operation, and uniformly coated layers. Some researchers focus on the effects of spin coating parameters such as wafer rotating speed, the viscosity of the coating liquid and solvent evaporation on final film thickness.In this work, the influence of substrate curvature on film thickness distribution is considered. A new parameter which represents the edge bead effect ratio（re） is proposed to investigate the influence factor of edge bead effect. Several operation parameters including the curvature of the substrate and the wafer-spin speed are taken into account to study the effects on the film thickness uniformity and edge-bead ratio. The morphologies and film thickness values of the spin-coated PDMS films under various substrate curvatures and coating speeds are measured with laser confocal microscopy. According to the results, both the convex and concave substrate will help to reduce the edge-bead effect significantly and thin film with better surface morphology can be obtained at high spin speed. Additionally, the relationship between the edge-bead ratio and the thin film thickness is like parabolic curve instead of linear dependence. This work may contribute to the mass production of flexible electronic devices.

Electrical Properties of Nano-TiO₂Thin Film Using Spin Coating Method

This work investigated the electrical properties of TiO2 thin film on empty glass and ITO glass by spin coating method. Highly transparent titanium oxide thin films were prepared on empty glass and Indium Tin Oxide (ITO) from a titanium (III) chloride precursor. The sheet resistance of the film prepared from both the synthesised and the commercially available TiO2 was measured by the Keithley four-point probe tester (KFPPT). A comparable sheet resistance of 10.69E + 00 Ω/sq was obtained on the ITO. The electrical conductivity of the TiO2 film on ITO glass substrate was found to be very high (3.46E + 05 Ω-1?cm-1) and comparable to that of the bare ITO glass.

Structure distortion, optical and electrical properties of ZnO thin films co-doped with Al and Sb by sol-gel spin coating

ZnO thin films co-doped with A1 and Sb with different concentrations and a fixed molar ratio of AlCl3 to SbCl3 at 1：2, are prepared by a sol-gel spin-coating method on glass annealed at 550 ℃ for 2 h in air. The x-ray diffraction results confirm that the ZnO thin films co-doped with Al distortion, and the biaxial stresses are 1.03× 10^8. 3.26× 10^8 and Sb are of wurtzite hexagonal ZnO with a very small 5.23 × 10^8, and 6.97× 10^8 Pa, corresponding to those of the ZnO thin films co-doped with Al and Sb in concentrations of 1.5, 3.0, 4.5, 6.0 at% respectively. The optical properties reveal that the ZnO thin films co-doped with Al and Sb have obviously enhanced transmittance in the visible region. The electrical properties show that ZnO thin film co-doped with Al and Sb in a concentration of 1.5 at% has a lowest resistivity of 2.5 Ω·cm.

Sol-Gel Spin Coating Synthesis of TiO₂Nanostructure and Its Optical Characterization

This work focuses on the sol-gel spin coating technique of TiO2 nanostructure synthesis and its characterization. Though various methods have been used to fabricate TiO2 nanostructure, much effort has not been exerted to achieve better photoresponsive and narrowly dispersed TiO2 nanostructure using the sol-gel spin coating method. Therefore, it is imperative to realize the synthesis of TiO2 nanostructures, and investigate their properties. In this work, TiO2 is synthesized by sol-gel spin coating technique using titanium tetraisopropoxide, isopropanol, acetic acid and deionized water as starting materials and deposited on borosilicate glass substrates. The effects of annealing temperatures (300˚C, 400˚C and 500˚C) on the structural and optical properties of the films were investigated by different techniques: Scanning Electron Microscopy (SEM), optical microscopy and UV-visible spectrophotometry. The optical characterization showed the direct band gap at 3.7 eV, 3.6 eV and 3.4 eV for 300˚C, 400˚C and 500˚C, respectively, and the optical transmittance and reflectance spectra showed a greater performance at 500˚C. The grain sizes obtained from SEM annealed at 300˚C, 400˚C and 500˚C are found to be about 6.0 nm, 5.0 nm and 4.0 nm respectively. The grain size of TiO2 nanostructure films decreased with increasing annealing temperatures. The results clearly indicated that the sol-gel spin coating synthesis of TiO2 nanostructure and post-thermal treatment at 500˚C cooled naturally at room temperature result in better photoresponsive and narrowly dispersed TiO2 nanostructure films with higher photoresponsive and good optical properties.

Structural, Optical and Luminescence Properties of ZnO Thin Films Prepared by Sol-Gel Spin-Coating Method： Effect of Precursor Concentration

Transparent zinc oxide（ZnO） thin films are fabricated by a simple sol-gel spin-coating technique on glass substrates with different solution concentrations（0.3-1.2 M） using zinc acetate dehydrate [Zn（CH_3COO）_2·2H_2O] as precursor and isopropanol and monoethanolamine（MEA） as solvent and stabilizer, respectively. The molar ratio of zinc acetate dehydrate to MEA is 1.0. X-ray diffraction, ultraviolet-visible spectroscopy and photoluminescence spectroscopy are employed to investigate the effect of solution concentration on the structural and optical properties of the ZnO thin films. The obtained results of all thin films are discussed in detail and are compared with other experimental data.

Effect of Spin Coating Speed on Some Optical Properties of ZnO Thin Films

This paper reports the synthesis and characterization of ZnO thin films prepared by sol-gel spin coating technique. The sol-gel was prepared from zinc acetate dehydrate as a precursor, 2-me- thoxyethanol as a solvent and di-ethanolamine as a stabilizer, and then deposited on glass substrate using spin coater at the coating speed of 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm and 6000 rpm. After pre-heated at 150℃, the samples were post-heated at 250oC and also annealed at 400℃. X-ray diffraction (XRD) of the films showed polycrystalline hexagonal structure, with (002) orientation as most intense peak having a grain size of 28.1 nm. The absorbance of the film decreases with increasing wavelength and the transmittance was generally high between visible regions from 280 nm - 1200 nm. The ZnO films deposited at a spinning speed of 2000 rpm had highest transmittance of 88% in the visible region from 280 nm - 1200 nm. The energy band gap was found to be in the range of 3.23 - 3.40 eV. The thicknesses of the films decreased with increase in coating speed. Based on these results, ZnO thin films obtained could have useful application in transparent conducting oxide electrode in solar cells.

Magnetic Properties of Nanometer-Scale NiZnCu Ferrite Thin Films Fabricated by Spray-Spin-Heating-Coating Method

A new nanometer-scale ferrite thin film with excellent high-frequency characteristics has been developed by the spray-spin-heating-coating method. The effects of the ion synthesis mechanism, chemical stoichiometry, fabrication method, and doping content on the magnetic properties and microstructure of the thin films have been analyzed. The films formed between 75℃ and 90℃ by spray-spin-heating-coating methods was discovered with fine grain size of about 21 nm, high saturation magnetization (4πMs) of about 6.5 kGs, coercivity of about 9.8 Oe, as well as initial permeability of about 14.0. These films can be widely used in radio-frequency integrated circuit devices.

Increasing Dye-Sensitized Solar Cell Efficiency by ZnO Spin-Coating of the TiO₂Electrode: Effect of ZnO Amount

This paper is concerned with the improvement of dye-sensitized solar cell (DSSC) efficiency upon ZnO-coating of the TiO2 electrode. Sol-gel ZnO of controlled amount by varying the number of sol drops during spin-coating is shown to increase the DSSC efficiency. The highest efficiency is obtained at a single sol drop with enhancement of 40%, while beyond this amount the efficiency falls down sharply to zero. Based on measured optical absorption spectra of the different dye-loaded electrodes, it is concluded that this amount of ZnO sol corresponds to the thinnest layer that can create the energy barrier to minimize the electron recombination rate without seriously affecting the dye adsorption efficiency of the TiO2 film.

MgO and ZnO Composite Thin Films Using the Spin Coating Method on Microscope Glasses

In this study, a new route to produce pure and composite ZnO-MgO thin films has been presented. In the process the pure ZnO thin films were the starting point, ending up with MgO by doping various percentages (from 0% to 100%) of Mg with the help of sol-gel spin coating technique. The crystal phases in all doping levels have been obtained when the samples annealed at 600℃ for a duration of 6 hours. The X-ray diffraction (XRD) spectra, the scanning electron microscopy (SEM) micrographs and UV-Vis absorption spectra have been performed to elucidate the composed film structures.

ZnO Spin-Coating of TiO₂Photo-Electrodes to Enhance the Efficiency of Associated Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) with ZnO spin-coated TiO2 photo-electrodes are compared to DSSC with a bare TiO2 photo-electrode. It is demonstrated that the deposited ZnO of controlled amount, by varying the precursor concentration in the coating sol, can indeed enhance the performance of the DSSC. The measured power conversion efficiency shows a maximum around the precursor concentration 0.1 M and falls down sharply to 0% beyond this point. The results are interpreted on the basis of two competing factors: At ZnO concentrations less than 0.1 M, the formation of an energy barrier increases the photocurrent by reducing the rate of interfacial back-recombination. At ZnO concentrations greater than 0.1 M, the screening of the TiO2 film by thicker ZnO layers decreases the photocurrent through the reduction of TiO2 dye-adsorption efficiency.

Structural and optical properties of nano-spin coated sol-gel porous TiO_2 films

Three thicknesses of TiO2 films, 174, 195, and 229 nm, were deposited onto quartz substrates by sol–gel spin coating method. The as-deposited thin films were characterized by nano-crystallite with different sizes (19–46 nm) and relatively high porous structure. Optical constants were determined and showed the lowest refractive index of 1.66 for the as-prepared films that ever reported till now. Obtained results were discussed through current theoretical ideas.

Low Temperature Gas Sensing Coatings Made Through Wet Chemical Deposition of Niobium Doped Titanium Oxide Colloid

Niobium doped titanium oxide (TiO2) colloid was synthesized to fabricate a hydrogen gas sensor layer on oxidized silicon wafer substrate. The layers were obtained using spin coating technique and then heated in air at 500°C for 30 min. The doping of TiO2 led to a significant enhancement of the sensitivity of the layer especially at low operating temperature. The effect of doping was found effective of operating the sensor at relatively low temperature (150°C). The layers show a very smooth nanostructure with average roughness of less than 0.5 nm. The behavior of the sensing characteristics of such layers was discussed related to their chemical compositions, morphology and their crystalline structure. The morphological and structural characteristics of the layers were studied through X-ray diffraction (XRD) and Atomic force microscopy (AFM).

Opto-Electronic Investigation of Wet Coating Deposition of ITO Nanopowders on Flexible Substrate Using Pulse Nd-YAG Laser

Transparent thin layer indium tin oxide was coated on polyethylene tetraphetalate (PET) substrate by means of spin coating process and its opto-electronic properties have been investigated. The surface treated by pulse Nd-YAG laser. Pulse frequency, duration and energy were, 1000 Hz, 0.2 to 20 ms and 25 to 40 J respectively. The effect of treatment on crystallization, optical properties and bonding processes of the thin layer was investigated. The results show that ITO coated on flexible PET substrates is conductive and transparent. The sheet transparency for a 350 nm thickness in the visible range is more than 83.6%. Using Nd-YAG laser increased conductivity by a factor of 100 times and causes higher bonding performances.

Polymer solar cells based on a PEDOT:PSS layer spin-coated under the action of an electric field

In the process of fabrication of polymer photovoltaic （PV） devices, poly （3, 4-ethylenedioxythiophene）： poly（styrenesulfonate） （PEDOT：PSS） thin film, acting as an anode buffer layer, is spin-coated under the action of an electric field. The PV devices with a PEDOT：PSS layer spin-coated under the action of a static electric field exhibit improved short-circuit current density （Jsc） and power conversion efficiency （PCE）. The investigation of morphology shows that the appropriate intensity of the electric field can increase the roughness of the surface of the PEDOT：PSS layer, which results in improved contact between the anode and hole transport layer and thus enhances the Jsc of the devices. Chemical analysis is also provided by x-ray photoelectron spectroscopy （XPS） spectra.

旋涂法制备柔性聚酰亚胺基板实验设计

为进一步提高学生的实践能力和综合分析能力,我们以目前平板显示(Flat-Panel Display,FPD)领域应用最广泛的柔性聚酰亚胺(Polyimide,PI)为实验对象,采用旋涂工艺制备柔性的聚酰亚胺薄膜,通过激光扫描共聚焦显微镜(Confocal Laser Scanning Microscope,CLSM)、原子力显微镜(Atomic Force Microscope,AFM)、紫外-可见光分光光度计(Ultraviolet-Visble Spectrophotometer,UV-vis)、拉力试验机(Tensile Tester,TT)及傅里叶变换红外光谱仪(Fourier Transform Infrared Spectroscopy,FTIR)对所得薄膜进行表征。这样的实验设计具有明显的前沿性和综合性,让学生能深入理解PI材料的优秀性能和独特作用。本实验可以承担本科教育与行业生产之间的桥梁,使得二者相互促进,共同发展。