Effect Of Spinning Speed Research Articles

Effect of Spin Speed on the Physical Characteristics of CuO Films Synthesized by Sol–Gel Spin Coating for H2S Gas Sensing

Effect of Spin Speed on the Physical Characteristics of CuO Films Synthesized by Sol–Gel Spin Coating for H2S Gas Sensing

Optimizing Spin-Coat Speed for Fabrication of P3HT: PCBM Solar Cells

The effect of spin speed on the orientation of the conjugated polymer chains becomes a matter of concern while fabricating bulk heterojunction devices such as solar cells. The stability and performance strongly depend on the intertwining of the two molecules that form the bulk heterojunctions. In the case of P3HT: PCBM, it is the long chains of P3HT that encompasses the PCBM molecules. This work investigates the fabricating conditions of Poly (3-hexylthiophene) (P3HT) on the glass substrates in terms of spin coating speeds to obtain favourable geometry of P3HT. For this purpose, three different samples were prepared, keeping spin rate as 6850, 8150 and 9700 rpm, respectively. It was observed that at high spin rates, a large centrifugal force acts upon polymer chains, unfolding them into highly oriented structures. These P3HT chains are free from twists, kinks and are not intermingled. The results of the present work advocate fabricating P3HT: PCBM films at spin speeds less than 6850 rpm.

Correction: Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Correction: Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Preparation and study of the structural and optical traits of Ag: Zro2 nanostructure thin films prepared via spin coating: Effect of spin speed on thin films properties

Thin films of silver: zirconium oxide (Ag: ZrO2), prepared using the spin coating method (SCM) with 2% silver nitrate (Ag NO3) and 1% zirconium nitrate (Zr (NO3) 4) on glass substrate at room temperature, with different spin speeds (1000, 2000 and 3000) rpm. X-ray diffraction (XRD) and Field Emission scanning electron microscopy were used to investigate the structural properties of the grown silver films. The optical properties of these thin films were distinguished by UV-vis spectroscopy. The films' polycrystalline nanostructure was revealed by X-rays, and the grain size shrank with increasing spin speed (from 1000 to 3000 rpm). The scanning electron microscope showed that the average particle size also decreases from (80.7 - 42.67) nm with an increase in the spin speed from (1000 - 3000). and Uv-vis spectroscopy showed that the transparency of the films increases, while the absorbance, coefficient attenuation, and absorption coefficient of the films decrease when the spin speed increases

Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Characterization of Tin Disulfide Thin Films Prepared by Spin Coating Technique: Effect of Spin Speed and Deposition Time on Film Properties

Effect of spin speed on the properties of TiO2 thin films

In this study, TiO2 thins films were fabricated by using a spin coating technique, made possible by varying the spin speed. An investigation of the effects of spin speed on the structural and optical properties of thin films of TiO2 is carried out. In all the synthesized thin films, the X-Ray pattern shows an anatase phase of TiO2. The FTIR spectrum also confirms the formation of TiO2. According to UV–Vis spectroscopy, the band gap increases with spin speed. The band gap decreases for the sample prepared at 2500 rpm. Based on the results obtained, it can be concluded that TiO2 films are suitable for gas sensor applications.

Using Otsu's Method for Image Segmentation to Determine the Particle Density, Surface Coverage and Cluster Size Distribution of 3 nm Si Nanoparticles

The deposition techniques of silicon nanoparticles (Si-NPs) have been widely researched because of the plethora of promising applications. An accurate calculation of the nanoparticle density is of paramount significance for the understanding of device performance. In this work, we statistically evaluate the deposition of 3 nm Si-NPs via spin coating and drop casting. We image the Si-NP samples using optical microscopy combined with ultra-violet illumination, under which they exhibit red photoluminescence. We then perform image segmentation through a computer vision technique, particularly Otsus method, which works by detecting an automatic threshold value to segment the micrograph into its foreground (Si-NPs) and background (substrate). Finally, we utilize a counting algorithm to determine the particle density, surface coverage and cluster size distribution (CSD) on each sample, and hence evaluate the outcome of the two deposition techniques. For spin coating, the effect of drop volume (from 505 L to 2505 L) at constant speed, and the effect of spin speed (100, 300, 400 and 500 RPM) are both investigated while for drop casting, drop volumes of 100, 300 and 500 L were examined. It was found that the nanoparticle cluster density increases with increasing volume until 300 L while increasing the spin speed decreases the cluster of NPs deposited but results in higher uniformity of particle distribution. For spin coating, the highest cluster density recorded was 410⁶ particles/cm² for the sample with 1005 L at a speed of 400 RPM while for drop casting it was 8.7510⁶ particles/cm² at a volume of 300 L. Moreover, the relation between particle density, size distribution and the deposition techniques is discussed in terms of the strong centrifugal force the particles experience during spin coating compared to drop casting, as well as the interdependency of bonding of the Si-NPs with the solvent molecules on the deposition efficiency.

Spin Coating Immobilisation of C-N-TiO2 Co-Doped Nano Catalyst on Glass and Application for Photocatalysis or as Electron Transporting Layer for Perovskite Solar Cells

Producing active thin films coated on supports resolves many issues of powder-based photo catalysis and energy harvesting. In this study, thin films of C-N-TiO2 were prepared by dynamic spin coating of C-N-TiO2 sol-gel on glass support. The effect of spin speed and sol gel precursor to solvent volume ratio on the film thickness was investigated. The C-N-TiO2-coated glass was annealed at 350 °C at a ramping rate of 10 °C/min with a holding time of 2 hours under a continuous flow of dry N2. The C-N-TiO2 films were characterised by profilometry analysis, light microscopy (LM), and scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). The outcomes of this study proved that a spin coating technique followed by an annealing process to stabilise the layer could be used for immobilisation of the photo catalyst on glass. The exposure of C-N-TiO2 films to UV radiation induced photocatalytic decolouration of orange II (O.II) dye. The prepared C-N-TiO2 films showed a reasonable power conversion efficiency average (PCE of 9%) with respect to the reference device (15%). The study offers a feasible route for the engineering of C-N-TiO2 films applicable to wastewater remediation processes and energy harvesting in solar cell technologies.

Effects of spin coating parameters on stress, electrical and optical properties of multilayer ZnO thin film prepared by sol–gel

In this study, zinc oxide (ZnO) thin films deposited on to glass substrates have been manufactured by sol–gel spin coating method at various spin speed and time. The effect of spin speed and time on film thickness, structural properties, and residual stress parameters has been investigated. Scanning electron microscope investigations have shown that the thickness of films has changed depending on coating parameters. X-ray diffraction measurements have indicated that polycrystalline films have formed with hexagonal wurtzite structure on the sample surfaces. The values of residual stress on the ZnO film have enhanced with increasing coating speed and also decreased with increasing film thickness. The UV transmittance of the prepared thin films has changed between 70% and 95% depending on the coating speed and time. The fluorescence measurements of the thin films have been determined in the spectral range from 350 nm to 900 nm. It has been observed that the fluorescent intensity has a high value in 2000 rpm-50 s. Furthermore, the electrical conductivities of the ZnO films have increased by diminishing the film thickness.

Robust spin coating deposition process for paraffin phase-change films

In this work, for the first time, a cost-effective and resource-light spin coating process for the fabrication of the paraffin films on silicon and glass substrates is reported. Paraffin or alkane is a mechanical phase-change material (PCM) that undergoes approximately 15% reversible volumetric change through its solid-liquid transition. In addition, it is a low-loss dielectric with a loss tangent of 6 × 10−4 at 100 GHz which is a critical feature for certain radio frequency (RF) tunable devices. Traditionally physical vapor deposition techniques are used for paraffin PCM films. Here, an innovative and alternative process using spin coating is developed that overcomes the challenges imposed by the phase-change properties of the material. Spin coating of two types of paraffin—eicosane and hexatriacontane—on silicon, Pyrex and gold-coated substrates are studied. P-xylene is chosen as the solvent due to the solubility of eicosane and hexatriacontane at temperatures lower than its melting point. Effect of spin speed, spin time, substrate temperature, solution concentration, and substrate type on roughness and thickness of paraffin films are reported. Developed process offers a fast, repeatable, and resource-light deposition technique for hexatriacontane which can be utilized in developing several classes of new devices including low-loss RF architectures.

High temperature, transparent, superhydrophobic Teflon AF-2400/Indium tin oxide nanocomposite thin films

The outstanding properties of Teflon AF-2400—chemical, optical, etc—inspired us to make modifications to enhance its hydrophobicity. We prepared an AF-2400/indium tin oxide (ITO) nanocomposite by a spin coating technique at room temperature, using the AF-2400 polymer as the matrix and ITO nanoparticles as the filler. Different ITON concentrations ranging from 3 to 30 mg ml−1 were prepared to study the effect of nanoparticle loading on the films’ properties and superhydrophobicity. The effect of spin speed and annealing temperature was also studied. Atomic force microscopy, x-ray photoelectron spectroscopy, and UV–vis analysis were employed to characterize the prepared films. The results indicated that the film’s low surface energy and nano/micro-features made it superhydrophobic. Increasing the ITON concentration to 15 mg ml−1 improved the superhydrophobicity of the composite film by increasing the surface roughness. The coating showed superhydrophobic behavior with a static contact angle (SCA) around 152° and contact angle hysteresis less than 2°. The nanocomposite films also exhibited excellent thermal stability, sustaining temperatures as high as 240 °C without losing their superhydrophobic behavior. Three models, Wenzel, Cassie–Baxter, and Shuttleworth–Bailey, were used to predict the SCA. The results confirmed that the latter model gave the best prediction. In addition to superhydrophobicity, the AF-2400/ITON films coated on a glass substrate showed very high transparency—around 95% in the visible and infrared ranges. An effective medium theory, the Bergman representation, was used to simulate the transmittance of the AF-2400/ITON nanocomposites. The measured and simulated transmittance values were in good agreement in the visible range. Based on our results, this coating may be highly useful for many practical applications, including solar cell coatings, chemical resistance protective coatings, and more.

Comprehensive analysis of spin coated copper zinc tin sulfide thin film absorbers

Copper zinc tin sulfide (Cu2ZnSnS4, CZTS) thin films have been widely studied recently due to the advantages of low-cost, high absorption coefficient (≥104 cm−1), suitable band gap (∼1.5 eV) and non-toxicity. This promising kesterite semiconductor structure can also be fabricated using spin coating methods that do not require vacuum and high technology. So far, a comprehensive parameter analysis about the growth of spin-coated CZTS absorbing layers has been lacking in the literature; therefore, here the effects of spin speed, solution molarity, amount of stabilizer, drying and subsequent annealing parameters on the films were investigated in terms of composition, grain size, surface morphology, crystallinity and film thickness. It has been found that the spin speed and molarity are effective on the film quality, but this effect is not sufficient. The quality of the prepared CZTS thin film is largely dependent on the heat treatment. Various drying, annealing temperatures and atmospheres were used and optimum heat treatment parameters obtained. As a result, spin coating and subsequent heat treatment parameters for the stoichiometric CZTS thin film absorber layer were determined.

Investigation of ZnO nanostructures: effect of metal and spinning speed on the physical properties

In this current work, we report on the surface morphology of pure (ZnO) and metal doped (MZO, M = Cu, Fe and Cd) zinc oxide nanostructures grown by sol-gel spin coating route onto a glass substrate at room temperature and speed of 1,000 rpm. We also investigate the effect of spinning speed on the physical and surface properties of coated ZnO films. The doping ratios Cu/Zn, Fe/Zn, Cd/Zn were kept at 2% in the solution. Atomic force microscope (AFM) revealed that nano-grains change in shape and growth orientation as a result of metal content. Average of grains sizes were found to be 87, 122, 174 and 260 nm respectively for pure, Cu, Fe and Cd doped ZnO. Based on the histogram profile, the shape looks like Gaussian curve for the pure ZnO, and it changes considerably for the M-doped ZnO films. Parameters of surface are investigated such as distribution of heights, power spectrum density (Psd), Fourier transform (Ft) of the picture and surface roughness (Rms). Spinning speed influences the surface and physical properties of coated ZnO films. The optimum results, high transparency (~72%) and low resistivity (9 kWcm), have been obtained with an increase in speed.

HIGH PRECISION INTERFEROMETRIC THICKNESS ANALYSIS OF SUB-MICROMETERS SPIN-COATED POLYEPOXYPROPYLCARBAZOLE FILMS

This paper deals with the interferometric thickness measurements of the spin-coated submicrometer polymer films based on polyepoxypropylcarbazole. The measuring system including the conventional microinterferometer MII-4 with attached webcamera and software for the high precision measurement of the submicrometer thicknesses of films was designed and developed. Different concentrations of polymer solution and spin speed were used in order to obtain thin films with thicknesses in the range from 160 nm to 960 nm. It was shown that there was a linear dependence of obtained film thickness on polymer solution concentration, but the significant effect of spin speed on film thickness wasn't observed.

High-Performance Triisopropylsilylethynyl Pentacene Transistors via Spin Coating with a Crystallization-Assisting Layer

The effects of spin speed and an amorphous fluoropolymer (CYTOP)-patterned substrate on the crystalline structures and device performance of triisopropylsilylethynyl pentacene (TIPS-PEN) organic field-effect transistors (OFETs) were investigated. The crystallinity of the TIPS-PEN film was enhanced by decreasing the spin speed, because slow evaporation of the solvent provided a sufficient time for the formation of thermodynamically stable crystalline structures. In addition, the adoption of a CYTOP-patterned substrate induced the three-dimensional (3D) growth of the TIPS-PEN crystals, because the patterned substrate confined the TIPS-PEN molecules and allowed sufficient time for the self-organization of TIPS-PEN. TIPS-PEN OFETs fabricated at a spin speed of 300 rpm with a CYTOP-patterned substrate showed a field-effect mobility of 0.131 cm(2) V(-1) s(-1), which is a remarkable improvement over previous spin-coated TIPS-PEN OFETs.

Sol–gel derived zinc oxide films: Effect of deposition parameters on structure, microstructure and photoluminescence properties

ZnO films were prepared by sol–gel method and deposited onto glass substrates with spin coating system. XRD patterns and FESEM analysis were used to investigate the effect of deposition parameters such as spin speed and molar concentration on the crystallinity and surface morphology of the films. XRD patterns show that ZnO films are polycrystalline with type-wurtzite hexagonal structure. The film which is deposited at 4000 rpm and with 0.5 M sol has the best crystallinity. The FESEM micrographs showed that the surface morphology of the films was not significantly affected from the spin speed. FESEM micrographs showed that the crystallite sizes of 1000, 4000 and 5000 rpm are almost same. But 2000 and 3000 rpm have lower crystallite sizes than the others. Also, the amount of voids in the 1 M was found higher. The effect of spin speed and molar concentration on the optical properties of ZnO films was investigated by PL spectroscopy. The electrical properties of the ZnO films were investigated by using two probe methods in dark. The highest conductivity values were obtained for ZnO films prepared by 4000 spin speed and 0.5 M of concentration.

Effect of Spin Speed and Solution Concentration on the Directed Assembly of Polymer Blends

Directed assembly of polymer blends using chemically heterogeneous patterns during spin-coating can be used to produce nanopatterned polymer structures. Well-ordered morphologies are obtained when the characteristic length of a polymer blend is commensurate with pattern periodicity. In this paper, spin-coating speed and solution concentration were used to control the characteristic length of a polystyrene (PS)/poly(acrylic acid) (PAA) blend. With increasing spin speed or reducing solution concentration, the characteristic length decreased. Critical spin speeds or solution concentrations that produced the required characteristic length commensurate with the given pattern periodicity were predicted. Well-ordered morphologies were obtained when spin speed or solution concentration was close to the critical value. A new method of image analysis was introduced to quantitatively evaluate the quality of replication of the underlying pattern. The range of commensurability between characteristic length and pattern...

ChemInform Abstract: High-Resolution 27Al and 29Si MAS NMR Investigation of SiO2-Al2O3 Glasses

{sup 27}Al and {sup 29}Si MAS NMR spectra have been obtained for SiO{sub 2}-Al{sub 2}O{sub 3} glasses quenched from the melt at two rates: 10{sup 5}-10{sup 6} {degree}C s{sup {minus}1} (SQ) and 10{sup 2}-10{sup 3} {degree}C s{sup {minus}1} (NQ). TEM experiments detected phase separation in the S{sub 76}A{sub 24}SQ and S{sub 52}A{sub 48} SQ samples but no phase separation for the S{sub 41}A{sub 59} SQ composition. The NQ glasses were phase separated and, in the diffraction TEM experiments, showed diffuse spots indicating microcrystallinity. {sup 27}Al spectra for the SQ glasses show three peaks due to aluminum in 4-, 5-, and 6-coordination, whereas NQ glasses show only peaks associated with aluminum in 4- and 6-coordination. Quantitative results for the {sup 27}Al spectra are discussed. The effect of spin speed on the {sup 27}Al MAS NMR spectra for SQ and NQ samples is demonstrated. Magnitudes of mean quadrupolar coupling constants and mean isotropic chemical shifts have been estimated. {sup 29}Si spectra of SQ glasses reveal a distribution of 4-coordinate Si sites, whereas NQ glasses show two inequivalent 4-coordinate sites.

Combined Effect of Spin Speed and Ionic Strength on Polyelectrolyte Spin Assembly

Polyelectrolyte spin assembly (PSA) of multilayers is a sequential process featuring adsorption of oppositely charged polyelectrolytes from dilute solutions undergoing spin-coating flow. Here, we report on the dependence of PSA multilayer buildup of poly(sodium 4-styrenesulfonate) and poly(allylamine hydrochloride) on solution ionic strength and spin speed. We observed that at a given spin speed, the PSA coating growth rate (thickness/bilayer) and polymer surface coverage shows a nonmonotonic dependence on salt concentration, first increasing and then decreasing with increasing solution ionic strength. This is argued to be a manifestation of two competing mechanisms responsible for the layer formation. At low salt concentrations, the electrostatic interactions control the multilayer assembly process, while at high salt concentrations it is dominated by shear flow. We explain this nonmonotonic behavior in the framework of a Flory-like theory of multilayer formation from polyelectrolyte solution under shear flow. Additionally, the PSA process led to multilayer coatings with a radial dependence on thickness at lower spin speed in the shear-dominated regime. On increasing spin speed, such radial dependence subsided, eventually leading to uniform coatings by planarization. The surface topography of the multilayered coatings adsorbed at salt concentration less than 0.1 M was flat and featureless for all studied spin speeds. Unique morphological features in the films were formed at salt concentration higher than 0.1 M, the size of which depended on the spin speed and solution ionic strength.