Ellipsometric Imaging of Drying Sol-Gel Films

1988 ◽  
Vol 121 ◽  
Author(s):  
Alan J. Hurd ◽  
C. Jeffrey Brinker
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Dip Coating ◽  
Drying Process ◽  
Imaging Ellipsometry ◽  
Withdrawal Velocity ◽  
Coated Film ◽  
Sol Gel Films ◽  
Physical And Chemical ◽  
Dip Coated Films

ABSTRACTAlthough controlled dip-coating is an established way to apply high quality uniform coatings, the details of the coating and drying process have not been deeply studied. Depending on the physical and chemical state of the sol and the parameters of dipping (dipping angle and speed), a variety of thicknesses and porosities can be achieved [1]. For optical coatings, the refractive index and optical thickness can thereby be controlled.We have developed a method to view the drying front of a dip-coated film using broad beam ellipsometry [2], or “ellipsometric imaging.” In dip-coated films we take full advantage of the fact that a steady state is quickly reached where the drying line velocity matches the withdrawal velocity; however, the technique might also be used in unsteady situations such as spin coating. Imaging ellipsometry makes it possible to measure the refractive index and thickness profiles of both wet and dry films point-by-point in an entire image at once. These profiles provide important clues as to the relative importance of gravity, evaporation and other phenomena.

Sol-Gel Films With Tailored Microstructures

1992 ◽  
Vol 271 ◽  
Author(s):  
Deborah L. Logan ◽  
Carol S. Ashley ◽  
C. Jeffrey Brinker
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Film Deposition ◽  
Organic Species ◽  
Fractal Clusters ◽  
Acid And Base ◽  
Before And After ◽  
Sol Gel Films ◽  
Film Porosity ◽  
Dip Coated Films

ABSTRACTThe refractive index and porosity of silicate films formed by dip-coating were tailored by varying the aging time of a two-step acid- and base-catalyzed sol to control the size and structure of the polymeric species prior to coating. 29Si NMR showed that there was a 2% increase in the total number of bridging oxygens with sol age, consistent with a cluster-cluster growth mechanism. However, several percent monomer remained regardless of aging. Dip-coated films were characterized by ellipsometry before and after heating to moderate temperatures at three rates. Sol aging prior to film deposition leads to greater film porosity, consistent with the concept of aggregation of fractal clusters, but only after a heat treatment to remove the organic species associated with incompletely hydrolyzed monomers from the pores.

scholarly journals Mode Sensitivity Exploration of Silica–Titania Waveguide for Refractive Index Sensing Applications

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7452
Author(s):  
Muhammad A. Butt ◽  
Andrzej Kaźmierczak ◽  
Cuma Tyszkiewicz ◽  
Paweł Karasiński ◽  
Ryszard Piramidowicz
Keyword(s):  
Refractive Index ◽  
High Performance ◽  
Near Infrared ◽  
Sol Gel ◽  
Cost Effective ◽  
Dip Coating ◽  
Infrared Wavelength ◽  
Refractive Index Sensing ◽  
Sensing Applications ◽  
Coating Method

In this paper, a novel and cost-effective photonic platform based on silica–titania material is discussed. The silica–titania thin films were grown utilizing the sol–gel dip-coating method and characterized with the help of the prism-insertion technique. Afterwards, the mode sensitivity analysis of the silica–titania ridge waveguide is investigated via the finite element method. Silica–titania waveguide systems are highly attractive due to their ease of development, low fabrication cost, low propagation losses and operation in both visible and near-infrared wavelength ranges. Finally, a ring resonator (RR) sensor device was modelled for refractive index sensing applications, offering a sensitivity of 230 nm/RIU, a figure of merit (FOM) of 418.2 RIU−1, and Q-factor of 2247.5 at the improved geometric parameters. We believe that the abovementioned integrated photonics platform is highly suitable for high-performance and economically reasonable optical sensing devices.

Changes of thickness and refractive index of silica sol-gel film by dip coating process

2014 ◽  
Vol 26 (7) ◽  
pp. 72005
Author(s):  
张日东 Zhang Ridong ◽  
严鸿维 Yan Hongwei ◽  
吕海兵 Lü Haibing ◽  
张尽力 Zhang Jinli ◽  
晏良宏 Yan Lianghong ◽  
...  
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Dip Coating ◽  
Silica Sol ◽  
Coating Process ◽  
Gel Film

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.

Nano-crystal V[sub 2]O[sub 5]nH[sub 2]O sol-gel films made by dip coating

2012 ◽  
Author(s):  
Orhan Özdemir ◽  
F. Pınar Gökdemir ◽  
U. Deneb Menda ◽  
Pelin Kavak ◽  
A. Evrim Saatci ◽  
...  
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Nano Crystal ◽  
Sol Gel Films

Modification of Sol-Gel Thin Films By Ion Implantation

1994 ◽  
Vol 346 ◽  
Author(s):  
Hiroshi Hirashima ◽  
Kenji Adachi ◽  
Hiroaki Imai
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Ion Implantation ◽  
Sol Gel ◽  
The Other ◽  
Ir Absorption ◽  
Absorption Bands ◽  
Chemically Modified ◽  
Sol Gel Films ◽  
Ion Species

ABSTRACTIn order to densify and to improve the physical properties, TiO2 sol-gel films, about 100 nm in thickness, on silica glass or silicon wafer were implanted with Ar+ or B+ ions. The refractive index of the as-dried films increased and the IR absorption band of OH disappeared after Ar+ implantation. Drying and densification of sol-gel films were enhanced by Ar+ implantation. On the other hand, the refractive index and the thickness of the films hardly changed with B+ implantation. However, IR absorption bands of B-O bond were observed after B+ implantation. This suggests that sol-gel films could be chemically modified by ion implantation with reactive ion species.

Improving of Tribological Properties of Nanocomposites Sol-Gel Thin Films by Fluorocyclophosphazene Derivatives

2005 ◽  
Author(s):  
G. Celichowski ◽  
K. Chrobak
Keyword(s):  
Thin Films ◽  
Tribological Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
Rf Plasma ◽  
Good Thermal Stability ◽  
Force Microscopy ◽  
Coating Method ◽  
Dip Coating Method ◽  
Sol Gel Films

Fluorocyclophospazenes’ derivatives were used as modifiers for improving tribological properties of thin films prepared by sol-gel technique. Thin films were made on the base of aminopropyltriethoxysilane (APTS). All films were deposited by dip-coating method and post-treated by heat, UV radiation and low pressure of RF plasma. Chemical changes in sol-gel films during all steps of post-treatments and modifications were monitored by FT-IR spectroscopy and SIMS spectrometry. Topographies of modified surfaces were imaged by Atomic Force Microscopy (AFM). After final modification significant improvements of frictional properties were observed as well as their very good thermal stability.

Effect of heat treatment on formation of sol-gel (Pb, La)TiO3 films for optical application

1997 ◽  
Vol 12 (3) ◽  
pp. 812-818 ◽  
Author(s):  
Junmo Koo ◽  
Sung-Uk Kim ◽  
Dae Sung Yoon ◽  
Kwangsoo No ◽  
Byeong-Soo Bae
Keyword(s):  
Heat Treatment ◽  
Refractive Index ◽  
Film Thickness ◽  
Optical Transmission ◽  
Thick Films ◽  
Sol Gel ◽  
Propagation Loss ◽  
Optical Propagation ◽  
Lanthanum Titanate ◽  
Sol Gel Films

Lead lanthanum titanate [(Pb, La)TiO3] sol-gel films have been prepared to investigate the effect of heat treatment on the fabrication of uniform and crack-free thick films by applying different heating schedules. The surface morphology as well as the optical properties such as refractive index, optical transmission, and optical propagation loss of the films was examined, depending on the film thickness. Because the slower and longer heating is enough to remove the organic and nitrate residues and diminish the thermal shock while heating the films, slower and longer heating can produce the uniform and crack-free thick films having higher refractive index as well as lower optical propagation loss. Also, the drying and heating of the films on a hot plate in every coating resulted in the fabrication of thick films having above 8000 Å without any defects and microcracks. This film presented the highest refractive index as well as the lowest optical propagation loss which grows exponentially with increasing the film thickness due to the scattering of defects in the film.

Refractive Index Controlled Plasmon Tuning of Au Nanoparticles in SiO2-ZrO2 Film Matrices

2008 ◽  
Vol 8 (8) ◽  
pp. 3868-3876
Author(s):  
Sucheta De ◽  
Samar Kumar Medda ◽  
Goutam De
Keyword(s):  
Heat Treatment ◽  
Refractive Index ◽  
Au Nanoparticles ◽  
Sol Gel ◽  
Dip Coating ◽  
Uv Treatment ◽  
Final Heat ◽  
Molar Ratios ◽  
Glass Substrates ◽  
Heat Treated

Au-plasmon tuning has been accomplished by controlling the refractive index (n) of the embedding film matrix. The refractive index of the film matrices were controlled by changing the molar ratios of low (SiO2) and high index (ZrO2) components following sol–gel reactions. Thus, Au nanoparticles doped films were prepared from SiO2-ZrO2 inorganic–organic hybrid sols of variable molar ratios containing HAuCl4 following the dip-coating method. The film samples deposited on glass substrates were obtained after drying, UV-treatment, and subsequent heat-treatment at 500 °C in air. The nominal mol ratios of SiO2:ZrO2 were 1:0, 1:1, 1:2.3, and 1:4. 3 equivalent mol% Au–97% total oxide (SiO2 + ZrO2) was maintained in the final heat-treated films. FTIR studies confirmed good homogeneity of Si-Zr network in the Zr-containing films. The UV-treatment has been introduced to facilitate the decomposition of HAuCl4 in the hybrid matrix prior to the heat-treatment step. The main Au-plasmon peak, in the case of a SiO2 host (SiO2:ZrO2 = 1:0, n = 1.410), observed at about 546 nm, gradually red-shifted to 592 nm upon increasing the ZrO2 content (SiO2:ZrO2 = 1:4, n = 1.847). Transmission electron microscopy of the final heat-treated (500 °C) films showed existence of plate-like (triangular and hexagonal) Au nanoparticles (25–50 nm) along with relatively smaller nanoparticles of about 10 nm in size. X-ray diffraction patterns reveal that the Au nanoparticles have a (111) orientation.

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.

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