Standardization and control of a dip-coating procedure for optical thin films prepared from solution

1988 ◽  
Vol 66 (10) ◽  
pp. 861-867 ◽  
Author(s):  
Daniel W. Hewak ◽  
John W. Y. Lit.
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Waveguides ◽  
Volume Fraction ◽  
Composite Films ◽  
Solution Concentration ◽  
Dip Coating ◽  
Optical Quality ◽  
Withdrawal Rate ◽  
And Control

The properties of dip-coated thin films prepared from colloidal silica and titania solutions have been examined. The effects of withdrawal rate, heat treatment, and solution concentration on film thickness, refractive index, and other properties have been studied. Results show that extremely uniform and reproducible thin films with refractive indices between 1.46 and 2.08 and thicknesses up to 0.25 μm can be produced with a single dip. The refractive index of the SiO2:TiO2 composite films varies linearly with the volume fraction of TiO2, and the thickness varies linearly with withdrawal rate. The effects of drying on the final thin film properties are minimal; however, baking conditions have a significant effect, with films shrinking up to 50% and the refractive index increasing 40% during baking. The resulting films are hard, durable, and of good optical quality. We have studied these films for use as planar optical waveguides; however, the results are also applicable to films made for various uses such as optical coatings, filters, or protective layers.

scholarly journals Thin films of copper phthalocyanine deposited by solution processing methods

2020 ◽  
Vol 38 (1) ◽  
pp. 79-90
Author(s):  
Hubert Gojzewski ◽  
Fatemeh Ghani ◽  
Mirosław Szybowicz
Keyword(s):  
Thin Films ◽  
Copper Phthalocyanine ◽  
Substrate Surface ◽  
Spray Coating ◽  
Solution Concentration ◽  
Dip Coating ◽  
Solution Processing ◽  
Ambient Conditions ◽  
Processing Methods ◽  
Main Technique

AbstractIn this work, we show and discuss the surface structure picture of copper phthalocyanine (CuPc) thin films deposited from trifluoroacetic acid (TFA) solvent onto silicon substrates at ambient conditions by four solution processing methods, namely drop-casting, dip-coating, spin-casting and spray-coating. The CuPc films were studied by AFM, as the main technique, and complemented by micro-Raman spectroscopy. Essentially, such thin films consist of CuPc molecular nanoribbons of a fixed ~1 nm thickness. CuPc molecules are arranged in an in-plane direction and formed in stacks under a defined tilt angle with respect to the substrate surface (monolayer) or underlying CuPc layer (multilayer). The film morphology takes various forms depending on the solution concentration, number of layers, and the deposition method. For instance, the morphology varies from very wide (~600 nm) but flat (~1 nm) ribbons for films prepared by dip-coating to crystallized rod-like features (multi-layered ribbons) when obtained by spray-coating. The factors studied in this paper should be taken into consideration in designing and controlling the criteria for rigorous CuPc film architecture.

Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films

2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Silver Surface ◽  
Molar Ratios ◽  
Sol Gel Synthesis

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

Photocatalytic Degradation of Humic Acid Using Fe3+ and N-Doped 3SnO2/TiO2 Thin Films Coated on Glass Fibers

2014 ◽  
Vol 608 ◽  
pp. 164-169
Author(s):  
Peerawas Kongsong ◽  
Lek Sikong ◽  
Sutham Niyomwas ◽  
Vishnu Rachpech
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Humic Acid ◽  
Glass Fibers ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
High Photocatalytic Activity ◽  
Coating Methods ◽  
Uv Lamp

The Fe3+ and N–doped 3SnO2/TiO2 composite thin films and undoped films coated on glass fibers were prepared by sol–gel and dip–coating methods. The films were calcined at 600°C for 2 hour and characterized by XRD, SEM, EDS and XPS. The photocatalytic activity of the coated glass fibers was determined by means of degradation of a methylene blue (MB) solution and humic acid (HA). It was found that the optimized 20N/3SnO2/TiO2composite films exhibit a high photocatalytic activity and HA could be rapidly removed from water. The main factor affecting the HA degradation of 20N/3SnO2/TiO2 films is quantity of glass fibers loading, irradiation power of UV lamp and flow rate of water.

Silica/Silicone Nanocomposite Films: A New Concept in Corrosion Protection

1992 ◽  
Vol 274 ◽  
Author(s):  
Theresa E. Gentle ◽  
Ronald H. Baney
Keyword(s):  
Thin Films ◽  
Optical Microscopy ◽  
Composite Films ◽  
Dip Coating ◽  
Nanocomposite Films ◽  
Nanoporous Silica ◽  
Silica Films ◽  
Aluminum Panels ◽  
Organic Solutions ◽  
Salt Fog

ABSTRACTThin films of silsesquioxane, (HSiO3/2)n, were applied to aluminum panels and to CMOS microelectronic circuit surfaces by spin or dip coating organic solutions of the silsesquioxane. Nanoporous silica was obtained by oxidation of the silsesquioxane. These nanoporous silica films were then vacuum infiltrated with various viscosities of polydimethylsiloxanes (PDMS) to form hydrophobic nanocomposites. The nanocomposite films were shown to provide superior hermetic protection against salt fog exposure when compared to PDMS and silica films alone.The composite films were characterized by FTIR and optical microscopy. FTIR spectra showed that the silica served as a skeletal framework holding the hydrophobic PDMS in place and preventing loss of adhesion. This is in contrast to PDMS films alone in which blistering of the film from the substrate can occur, thus, allowing ions and moisture to reach the surface and corrosion to take place.

The Influencing Factors for the Thickness of Silica Sol-Gel Film by the Dip Coating Process

2014 ◽  
Vol 597 ◽  
pp. 165-169
Author(s):  
Jie Hong Lei ◽  
Ri Dong Zhang
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Refractive Index ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Sol ◽  
Coating Process ◽  
Power Functions ◽  
Withdrawal Speed ◽  
Gel Film

The porous sol-gel silica thin films were prepared on silicon substrate by the dip coating process. The surface roughness and microstructure of the film was measured by optical microscopy and AFM .Coating thickness and refractive index were measured by ellipsometry method. Influence of withdrawal speed and concentration of colloid was investigated for the thickness of silica. The relation of the thickness and withdrawal speed was fitted by the linear and power functions, and the results were analyzed and compared. It was found that the films with the same thickness prepared by different concentrations of colloid have different refractive indexes. The experimental results indicated that the thickness and refractive index of the film can be controlled by changing the withdrawal speed and colloid concentration.

Sol-Gel Pzt Films for Optical Waveguides

1991 ◽  
Vol 243 ◽  
Author(s):  
S.L. Swartz ◽  
S.D. Ramamurthi ◽  
J. R. Busch ◽  
V.E. Wood
Keyword(s):  
Refractive Index ◽  
Optical Waveguides ◽  
Sol Gel ◽  
Optical Loss ◽  
Ferroelectric Thin Film ◽  
Thin Film Deposition ◽  
Optical Quality ◽  
Film Deposition ◽  
Pzt Films ◽  
Degree Of Orientation

AbstractSol-gel processing is a candidate ferroelectric thin-film deposition method for electronic and electro-optic applications. At Battelle, sol-gel PbTiO3 and Pb(Zr,Ti)O3 films have been prepared on sapphire and single-crystal SrTiO3 substrates. Films deposited and annealed on sapphire substrates are crystalline with the perovksite structure and minimal crystallographic orientation, whereas films deposited on isostructural and lattice-matched SrTiO3 substrates exhibit a high degree of orientation. Guided-mode refractive index measurements were made using a single-prism method and film indices were computed. Refractive index values measured for PbTiO3 films (n = 2.58) and PZT films (n = 2.50) were slightly lower than values expected on the basis of bulk measurements. In double-prism experiments, optical wavcguiding was achieved over distances up to 10 mm in oriented PZT films on [100] SrTiO3substrates. Optical loss of 19 dB/cm was measured on one of these film samples. Such films, given requisite improvement in optical quality, may be suitable for useful optical waveguide devices. An approach is presented for the integration of ferroelectric waveguides onto silicon and/or GaAs substrates.

Nano Composite PVA-TiO2 Thin Films for OTFTs

2013 ◽  
Vol 678 ◽  
pp. 335-342 ◽  
Author(s):  
S. Sathish ◽  
Bellan Chandar Shekar ◽  
B.T. Bhavyasree
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Composite Films ◽  
Gravimetric Method ◽  
Dip Coating ◽  
Polymer Matrices ◽  
Poly Vinyl Alcohol ◽  
Organic Thin Film ◽  
Composite Polymer ◽  
Amorphous Nature

Pure PVA and composite thin films of poly vinyl alcohol (PVA)/Titanium dioxide (TiO2) were prepared on pre-cleaned glass substrates by Dip Coating Technique (DCT) and Metal Organic Deposition Technique (MODT). EDS and FTIR spectrum were used to identify the composition of the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA. The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The bands observed around 847 cm-1 and 601cm-1 belong to the asymmetric stretching of Ti–O–Ti groups. The last band at 460 cm-1 is due to the bending mode of Ti–O–Ti. The bands covered by Ti-O were located at 540, 700 and 950 cm-1. From the FTIR spectra, it is observed that some of the peaks of composite films were shifted and some of them were disappeared with respect to the pure compounds. This results manifested the conclusion about the specific interactions in composite polymer matrices and hence the complexation. Thus, complex formation in the composite polymer matrices has been confirmed from this analysis. The thickness of the coated films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD-20), gravimetric method and cross checked by optical spectrophotometer. XRD spectra indicated the amorphous nature of the films. Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. Both as grown and annealed films showed predominantly amorphous nature. The observed surface morphology and thermal stability indicated that these films could be used as dielectric layer in organic thin film transistors.

Refractive Index and Extinction Coefficient of ZnO:Al Thin Films Derived by Sol-Gel Dip Coating Technique

2013 ◽  
Vol 334-335 ◽  
pp. 290-293 ◽  
Author(s):  
N. Baydogan ◽  
T. Ozdurmusoglu ◽  
Huseyin Cimenoglu ◽  
A.B. Tugrul
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Extinction Coefficient ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
Optical Parameters ◽  
Coating Technique ◽  
Glass Substrates ◽  
Dip Coating Technique

Doped ZnO:Al thin films were deposited on glass substrates by the solgel dip technique. Optical parameters such as the refractive index and the extinction coefficient tend to change with increasing annealing temperature.

Properties of TiO2 Thin Film Prepared by Sol-Gel Dip Coating

2015 ◽  
Vol 723 ◽  
pp. 528-531
Author(s):  
Jun Wang ◽  
Ling Yun Bai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Refractive Index ◽  
Optical Properties ◽  
Band Gap ◽  
Optical Band Gap ◽  
Sol Gel ◽  
Dip Coating ◽  
Gel Method ◽  
Glass Substrates

TiO2 thin films were prepared on glass substrates by sol-gel method. The effect of withdraw speed on the thickness and optical properties of TiO2 thin films was investigated. The films were transparent in the visible wavelength. The thickness of the TiO2 films was increased from 90 nm for the withdraw speed of 1000 μm/s to 160 nm for the withdraw speed of 2000 μm/s. While, The refractive index of the TiO2 thin film decreased from 2.38 to 2.07. It may be due to the porosity of the film was increased. The optical band-gap of the films was around 3.45 eV.

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