scholarly journals Modeling of Poly(methylmethacrylate) Viscous Thin Films by Spin-Coating

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 198
Author(s):  
Navid Chapman ◽  
Mingyu Chapman ◽  
William B. Euler
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Spin Coating ◽  
Design Space ◽  
Three Dimensional ◽  
Drying Rate ◽  
Process Mapping ◽  
Concentration Effects ◽  
Coating Solution ◽  
Toluene Concentration

A predictive film thickness model based on an accepted equation of state is applied to the spin-coating of sub-micron poly(methylmethacrylate) viscous thin films from toluene. Concentration effects on density and dynamic viscosity of the spin-coating solution are closely examined. The film thickness model is calibrated with a system-specific film drying rate and was observed to scale with the square root of spin speed. Process mapping is used to generate a three-dimensional design space for the control of film thickness.

scholarly journals Multifractal analysis of ZnO thin films doped with Mg deposited by sol-gel spin coating on a glass substrate

2021 ◽  
Author(s):  
Ştefan Ţălu ◽  
Samah Boudour ◽  
Idris Bouchama ◽  
Bandar Astinchap ◽  
Hamta Ghanbaripour
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Multifractal Analysis ◽  
Sol Gel ◽  
Three Dimensional ◽  
Hexagonal Wurtzite Structure ◽  
Morphological Properties ◽  
Zno Thin Films ◽  
Axis Orientation ◽  
Mg Doping

Abstract A multifractal analysis has been performed on the three-dimensional surface microtexture of the ZnO thin films doped with Mg deposited by sol-gel spin coating on glass substrates. The effects of Mg doping element with amounts of 0, 2, 4, and 5 % on structural and morphological properties of the coated films were investigated. From the X-ray diffraction pattern analysis, it was found that the obtained thin films had a polycrystalline hexagonal wurtzite structure with preferential c-axis orientation and increased grain size with increasing the Mg doping. From scanning electron microscopy (SEM) analysis, it can be concluded that the surface of coated thin films had dense and uniformly distributed grains of nanoscale without any cracks over all surfaces of coated firms. From atomic force microscope (AFM) analysis, it can be also concluded that the surface of coated thin films had a dense columnar grain growth uniformly distributed over the entire 1 µm ⋅ 1 µm - scanned area. The surface microtexture was characterized in terms of multifractal analysis.

scholarly journals Solvent Effect to the Uniformity of Surfactant-Free Salmon-DNA Thin Films

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1606
Author(s):  
Jake Richter ◽  
Moses Nnaji ◽  
Heungman Park
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Solvent Effect ◽  
Spin Coating ◽  
Physical Parameters ◽  
High Uniformity ◽  
Modified Dna ◽  
Coating Methods ◽  
Dna Solutions ◽  
Focused Beam

Fabrication of surfactant-modified DNA thin films with high uniformity, specifically DNA–CTMA, has been well considered via drop-casting and spin-coating techniques. However, the fabrication of thin films with pure DNA has not been sufficiently studied. We characterize the uniformity of thin films from aqueous salmon DNA solutions mixed with ethanol, methanol, isopropanol, and acetone. Measurements of thickness and macroscopic uniformity are made via a focused-beam ellipsometer. We discuss important parameters for optimum uniformity and note what the effects of solvent modifications are. We find that methanol- and ethanol-added solutions provide optimal fabrication methods, which more consistently produce high degrees of uniformity with film thickness ranging from 20 to 200 nm adjusted by DNA concentration and the physical parameters of spin-coating methods.

scholarly journals Optical parameters of amorphous arsenic triselenide multilayers prepared by spin coating

2017 ◽  
pp. 5133-5140
Author(s):  
Salah. M. M.Salman
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Glass Substrate ◽  
Room Temperature ◽  
Amine Salt ◽  
Optical Parameters ◽  
Multilayer Thin Films ◽  
Transmission Spectra ◽  
Coating Solution ◽  
Arsenic Triselenide

Multilayer thin films of amorphous arsenic triselenide (As2Se3) were obtained by spin coating solution of an amine salt in amide on glass substrate.  The deposited multilayers in the range of 500 to 1000 nm were optically characterized by measuring the transmission spectra at room temperature.  All used samples were baked and annealed for different periods of times and temperatures.  The effect of layers number, baking times and temperatures on optical parameters were investigated.  The thickness of the prepared samples up to four layers was ranging between 0.1 µm to 0.2 µm.

scholarly journals Fabrication by Spin-Coating and Optical Characterization of Poly(styrene-co-acrylonitrile) Thin Films

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1015
Author(s):  
Elizabeth Hedl ◽  
Ivana Fabijanić ◽  
Iva Šrut Rakić ◽  
Ivan Vadla ◽  
Jordi Sancho-Parramon
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Film Thickness ◽  
Spin Coating ◽  
Visible Range ◽  
Force Microscopy ◽  
Atomic Force ◽  
Linear Behavior ◽  
Concentrated Solution ◽  
Dependent Viscosity

The optical characteristics of poly(styrene-co-acrylonitrile) thin films obtained by spin-coating of polymer blend in tetrahydrofuran were investigated by spectroscopic ellipsometry, spectrophotometry, and atomic force microscopy. Film thickness can be broadly varied by changing the polymer concentration.The film thickness dependence on PSAN concentration shows a non-linear behavior that can be explained by a concentration-dependent viscosity. According to previously proposed models, prepared solutions are close to the concentrated solution regime. Films show a broad transparency range and refractive index independent of film thickness. The refractive index values range from 1.55 to 1.6 in the visible range. Thermal treatment revealed good stability of the films up to 220 °C and a progressive deterioration for larger temperatures, with evident damage at 300 °C. UV-induced photodegradation was observed and results showed a progressive decrease of transmittance in the range between 200 and 300 nm but PSAN thin films show no changes when exposed to light from a solar illuminator. These investigations indicate that PSAN is an excellent candidate for thin film polymer-based optical uses like interference coatings or encapsulation of solar cells.

Influence of Film Thickness and Annealing Temperature on Optical Properties of Nanostructured-TiO2 Thin Films Prepared by Sol–Gel Spin Coating Technique

2016 ◽  
Vol 16 (02) ◽  
pp. 1650028 ◽  
Author(s):  
A. A. A. Darwish ◽  
F. S. Abu-Samaha ◽  
Z. Mohamed ◽  
M. M. El-Nahass
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Spin Coating ◽  
Optical Constants ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Spin Coating Technique ◽  
Tio2 Thin Films ◽  
Coating Technique ◽  
Quartz Substrates

TiO2 powder was found to be polycrystalline with rutile system. TiO2 films were deposited on quartz substrates by a sol–gel spin coating technique. X-ray diffraction and transmission electron microscope results have confirmed that the TiO2 films have nanostructure nature. It is found the crystallite size increased with annealing temperature. The optical constants of nanostructured TiO2 films were found to be independent of film thickness in the range from 100[Formula: see text]nm to 500[Formula: see text]nm. It is found that the optical constants and the dielectric constant of the thin films were all affected by annealing temperature. The existing allowed optical transitions in the as-deposited and annealed films were found to be direct and indirect transitions. Finally, the bandgaps of the as-deposited film were found to decrease with the annealing temperature.

Rational solvent selection strategies to combat striation formation during spin coating of thin films

2001 ◽  
Vol 16 (4) ◽  
pp. 1145-1154 ◽  
Author(s):  
Dunbar P. Birnie
Keyword(s):  
Thin Films ◽  
Surface Tension ◽  
Spin Coating ◽  
Surface Composition ◽  
Solvent Vapor ◽  
Coating Solution ◽  
Selection Strategies ◽  
Convective Motions ◽  
The Impact ◽  
Composition Changes

Striation defects in spin-coated thin films are a result of unfavorable capillary forces that develop due to the physical processes commonly involved in the spin-coating technique. Solvent evaporation during spinning causes depletion at the surface of the more volatile solution components while simultaneous viscous out-flow occurs providing the main source of solution thickness reduction during any typical spinning run. The composition changes in the surface layer can either stabilize or destabilize the surface with respect to convective motions within the coating solution. Destabilization (and therefore possible striation formation) happens when the surface composition changes so that a larger surface tension will develop. Thus, a careful cross-referencing of solvent volatility with surface tension effects can help establish solution conditions that will prevent this instability from arising. A plot of solvent vapor pressure (Pv) versus solvent surface tension (σ) is introduced and utilized to help discuss the impact of solvent choice when making coatings via spin coating. One important result is that when desiring to deposit a coating having a surface tension of σsolid, then it is favorable to use a fully miscible solvent that has a higher surface tension (i.e., σliquid > σsolid). More complicated solution mixtures were also examined, including dual-solvent systems and water-containing systems.

Giant Anisotropy of Conductivity in Hydrogenated Nanocrystalline Silicon Thin Films

1998 ◽  
Vol 536 ◽  
Author(s):  
A. B. Pevtsov ◽  
N. A. Feoktistov ◽  
V. G. Golubev
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Percolation Theory ◽  
Nanocrystalline Silicon ◽  
Spatial Light Modulators ◽  
Light Emitting ◽  
Light Modulators ◽  
Silicon Thin Films ◽  
Longitudinal Conductivity ◽  
Transverse Conductivity

AbstractThin (<1000 Å) hydrogenated nanocrystalline silicon films are widely used in solar cells, light emitting diodes, and spatial light modulators. In this work the conductivity of doped and undoped amorphous-nanocrystalline silicon thin films is studied as a function of film thickness: a giant anisotropy of conductivity is established. The longitudinal conductivity decreases dramatically (by a factor of 109 − 1010) as the layer thickness is reduced from 1500 Å to 200 Å, while the transverse conductivity remains close to that of a doped a- Si:H. The data obtained are interpreted in terms of the percolation theory.

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