Bilayer PMMA antireflective coatings via microphase separation and MAPLE

2020 ◽  
Vol 41 (2) ◽  
pp. 164-173
Author(s):  
Yunlong Guo ◽  
Shuzhen Ren
Keyword(s):  
Microphase Separation ◽  
Incident Light ◽  
Visible Range ◽  
Laser Evaporation ◽  
Antireflective Coatings ◽  
Porous Network ◽  
Cross Sectional ◽  
Polymer Thin Film ◽  
Deposition Parameters ◽  
Surface Morphologies

Abstract A poly(methyl methacrylate) (PMMA) bilayer antireflective coating (ARC) is designed based on polymeric microphase separation and matrix-assisted pulsed laser evaporation (MAPLE). The spin-coated layer shows subwavelength porous network structures, after phase separation via annealing and removal of the polystyrene (PS) phase, while the MAPLE deposited surface layer exhibits a biomimic moth-eye structure on glass to trap the incident light. The elaborate spin coated structure can be controlled flexibly by changing the ratio of mixture, annealing time and temperature, and the moth-eye structure can also be tuned by deposition parameters. The transmittance of the ARC presents a maximum of 95.64% and an average of 94.81% in visible range. The moth-eye structure on glass substrate formed by nanoglobules makes positive contributions to the improvement of transmittance according to UV–Vis result and simulation. The wetting motion of PMMA globules is observed as well by the comparison of AFM surface morphologies and cross-sectional profiles of globules on glass and polymer thin film. This work is a novel attempt to fabricate bilayer ARC with two different structures by a single polymeric material and will provide new route for fabrication of multilayer ARCs.

Influence of Deposition Parameters on Surface Texturing of ZnO:Al Films Prepared by In-line RF Magnetron Sputtering

2009 ◽  
Vol 1210 ◽  
Author(s):  
Jun-Sik Cho ◽  
Young-Jin Kim ◽  
Jeong Chul Lee ◽  
Sang-Hyun Park ◽  
Kyung Hoon Yoon
Keyword(s):  
Magnetron Sputtering ◽  
Scattered Light ◽  
Incident Light ◽  
Rf Magnetron Sputtering ◽  
Wet Etching ◽  
Visible Range ◽  
Silicon Thin Film ◽  
Working Pressure ◽  
Deposition Parameters ◽  
Deposited Films

AbstractA systematic study on the effect of sputtering deposition parameters on material properties of Al doped ZnO (ZnO:Al) films prepared by an in-line rf magnetron sputtering and on surface morphology of the films after wet etching process was carried out. For application to silicon thin film solar cells as a front electrode, the as-deposited films were surface-textured by a dilute HCl solution to improve the light scattering properties such as haze and angle resolved distribution of scattered light on the film surfaces. The microstructure of as-deposited films is affected significantly by the working pressure and film compactness decreases with increasing working pressure from 1.5 mTorr to 10 mTorr. High quality ZnO:Al films with electrical resistivity of 4.25 × 10-4 Ω cm and optical transmittance of 80% in a visible range are obtained at low working pressure of 1.5 mTorr and substrate temperature of 100℃. Crater-like surface morphologies are observed on the textured ZnO:Al films after wet etching. The size and shape of craters are closely dependent on the microstructure and film compactness of as-deposited films. Haze values of the textured ZnO:Al films are improved in a whole wavelength of 300 – 1100 nm compared to commercial SnO2:F films (Asahi U type) and incident light on the textured films is scattered effectively with 30° angle.

FIB preparation of cross-sectional polymer thin film TEM samples

2008 ◽  
Vol 14 (S2) ◽  
pp. 996-997
Author(s):  
S Kim ◽  
A Minor
Keyword(s):  
Thin Film ◽  
New Mexico ◽  
Cross Sectional ◽  
Polymer Thin Film

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

Effect of Methane Flow Rate on the Microstructural and Mechanical Properties of Silicon Carbide Thin Films Deposited by Reactive DC Magnetron Sputtering

2010 ◽  
Vol 66 ◽  
pp. 35-40 ◽  
Author(s):  
Erdem Baskurt ◽  
Tolga Tavşanoğlu ◽  
Yücel Onüralp
Keyword(s):  
Magnetron Sputtering ◽  
High Speed ◽  
Profile Analysis ◽  
High Speed Steel ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Cross Sectional ◽  
Methane Flow Rate ◽  
Surface Morphologies ◽  
Sic Films

SiC films were deposited by reactive DC magnetron sputtering of high purity (99.999%) Si target. 3 types of substrates, AISI M2 grade high speed steel, glass and Si (100) wafer were used in each deposition. The effect of different CH4 flow rates on the microstructural properties and surface morphologies were characterized by cross-sectional FE-SEM (Field-Emission Scanning Electron Microscope) observations. SIMS (Secondary Ion Mass Spectrometer) depth profile analysis showed that the elemental film composition was constant over the whole film depth. XRD (X-Ray Diffraction) results indicated that films were amorphous. Nanomechanical properties of SiC films were also investigated.

scholarly journals Optical Properties of Spin-Coated TiO2Antireflection Films on Textured Single-Crystalline Silicon Substrates

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ryosuke Watanabe ◽  
Yohei Eguchi ◽  
Takuya Yamada ◽  
Yoji Saito
Keyword(s):  
Optical Properties ◽  
Crystalline Silicon ◽  
Low Cost ◽  
Incident Light ◽  
Antireflection Coating ◽  
Silicon Wafers ◽  
Reflectance Spectra ◽  
Visible Range ◽  
Single Crystalline Silicon ◽  
Single Crystalline

Antireflection coating (ARC) prepared by a wet process is beneficial for low cost fabrication of photovoltaic cells. In this study, we investigated optical properties and morphologies of spin-coated TiO2ARCs on alkaline textured single-crystalline silicon wafers. Reflectance spectra of the spin-coated ARCs on alkaline textured silicon wafers exhibit no interferences and low reflectance values in the entire visible range. We modeled the structures of the spin-coated films for ray tracing numerical calculation and compared numerically calculated reflectance spectra with the experimental results. This is the first report to clarify the novel optical properties experimentally and theoretically. Optical properties of the spin-coated ARCs without interference are due to the fractional nonuniformity of the thickness of the spin-coated ARCs that cancels out the interference of the incident light.

scholarly journals Polarization-Independent Metasurface Lens Based on Binary Phase Fresnel Zone Plate

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1467
Author(s):  
Xing Li ◽  
Jing Tang ◽  
Jonathan Baine
Keyword(s):  
Fresnel Zone ◽  
Incident Light ◽  
Polarization State ◽  
Zone Plate ◽  
Visible Range ◽  
Fresnel Zone Plate ◽  
Binary Phase ◽  
Nanophotonic Devices ◽  
Potential Applications ◽  
Polarization Independent

Based on the binary phase Fresnel zone plate (FZP), a polarization-independent metasurface lens that is able to focus incident light with any polarization state, including circular, linear, and elliptical polarizations, has been proposed and investigated. We demonstrate that the metasurface lens consisting of metal subwavelength slits can operate in a wide bandwidth in the visible range, and has a higher focusing efficiency than that of an amplitude FZP lens without phase modulation. A multi-focus FZP metasurface lens has also been designed and investigated. The proposed lens can provide potential applications in integrated nanophotonic devices without polarization limitations.

Corrosion of the Materials in Sulfuric Acid

2008 ◽  
Author(s):  
Hong Pyo Kim ◽  
Dong-Jin Kim ◽  
Hyuk Chul Kwon ◽  
Ji Yeon Park ◽  
Yong Wan Kim
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Hydrogen Production ◽  
Immersion Time ◽  
Cross Sectional ◽  
Corrosion Morphology ◽  
Nuclear Heat ◽  
Corrosion Behaviors ◽  
Materials Used ◽  
Surface Morphologies

The program for hydrogen production with high temperature nuclear heat has been launched in Korea since 2004. Iodine sulfur (IS) process is one of the promising processes for a hydrogen production because it does not generate a carbon dioxide and massive hydrogen production may be possible. However, the highly corrosive environment of the process is barrier to the application in the industry. Therefore, corrosion behaviors of various materials were evaluated in sulfuric acid to select appropriate materials compatible with the IS process. The materials used in this work were Ni base alloys, Fe-Si alloys, Ta, Au, Pt, Zr, SiC and so on. The test environments were boiling 50wt% sulfuric acid without/with HI as an impurity and 98wt% sulfuric acid. The surface morphologies and cross sectional areas of the corroded materials were examined by using SEM equipped with EDS. From the results of the weight loss and potentiodynamic experiments, it was found that a Si enriched oxide is attributable to a corrosion resistance for materials including Si in boiling 98wt% sulfuric acid. Moreover the passive Si enriched film thickness increased with the immersion time leading to an enhancement of the corrosion resistance. Corrosion behaviours of the material tested are discussed in terms of the chemical composition of the materials, a corrosion morphology and the surface layer’s composition.

scholarly journals Stearic Acid/Layered Double Hydroxides Composite Thin Films Deposited by Combined Laser Techniques

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4097
Author(s):  
Ruxandra Birjega ◽  
Andreea Matei ◽  
Valentina Marascu ◽  
Angela Vlad ◽  
Maria Daniela Ionita ◽  
...  
Keyword(s):  
Stearic Acid ◽  
Composite Films ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Laser Evaporation ◽  
Time Stability ◽  
Deposition Parameters ◽  
Component Material ◽  
Double Hydroxide ◽  
Double Hydroxides

We report on the investigation of stearic acid-layered double hydroxide (LDH) composite films, with controlled wettability capabilities, deposited by a combined pulsed laser deposition (PLD)-matrix-assisted pulsed laser evaporation (MAPLE) system. Two pulsed lasers working in IR or UV were used for experiments, allowing the use of proper deposition parameters (wavelength, laser fluence, repetition rate) for each organic and inorganic component material. We have studied the time stability and wettability properties of the films and we have seen that the morphology of the surface has a low effect on the wettability of the surfaces. The obtained composite films consist in stearic acid aggregates in LDH structure, exhibiting a shift to hydrophobicity after 36 months of storage.

EFFECTS OF SPRAY PYROLYSIS DEPOSITION PARAMETERS ON MORPHOLOGICAL, OPTICAL AND STRUCTURAL PROPERTIES OF WO3 NANOSTRUCTURED THIN FILMS

2020 ◽  
Vol 27 (09) ◽  
pp. 1950203
Author(s):  
ALI AKHAVAN MAVARDIANI ◽  
MOHAMMAD BAGHER RAHMANI
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Spray Pyrolysis ◽  
Precursor Solution ◽  
Cost Effective ◽  
Solution Concentration ◽  
Visible Range ◽  
Glass Substrates ◽  
Deposition Parameters ◽  
Vis Spectroscopy

In this experimental research, tungsten trioxide (WO3) thin films were deposited using ammonium tungstate ((NH4)2WO4) by a simple and cost-effective technique of spray pyrolysis on top of glass substrates. The surface morphology, structural and optical properties of prepared samples were studied using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) pattern analysis and UV–Vis spectroscopy techniques, respectively. Studied deposition parameters were: substrate temperature (300, 350, 400, 450 and 500∘C), concentration of the precursor solution (0.01, 0.02, 0.04, 0.08, 0.1 and 0.2[Formula: see text]M), volume of the precursor solution (50, 100, 150 and 200[Formula: see text]mL) and the effect of pulsed spraying at different concentrations (0.01, 0.1 and 0.2[Formula: see text]M). FESEM images showed that the surface morphology has formed like nested micro-fibrous rings with a uniform distribution all over the surface. The XRD patterns revealed that increasing the solution concentration to 0.2[Formula: see text]M shows some peaks which can be attributed to WO3 with the hexagonal crystal structure. Transmission spectra of the samples indicate that all of the prepared samples are transparent in the visible range, with the calculated direct bandgap ranging from about 2.93[Formula: see text]eV to 3.96[Formula: see text]eV, depending on the deposition conditions.

On the “Step Bunching” Phenomena Observed on Etched and Homoepitaxially Grown 4H Silicon Carbide

2011 ◽  
Vol 679-680 ◽  
pp. 358-361 ◽  
Author(s):  
Massimo Camarda ◽  
Andrea Severino ◽  
Patrick Fiorenza ◽  
Vito Raineri ◽  
S. Scalese ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Resolution ◽  
Cross Sectional ◽  
Hydrogen Etching ◽  
Step Bunching ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Transmission Electron ◽  
Surface Morphologies ◽  
Scanning Electron

Using several types of surface analysis (Optical profilometers (OP), Atomic Force Microscopies (AFM), Scanning Electron Microscopies (SEM) and cross-sectional high-resolution Transmission Electron Microscopies (TEM)) we analyze the surface morphologies of misoriented 4H silicon carbide after pre-growth hydrogen etching and homo-epitaxial growths. We observed the characteristic self-ordering of nano-facets on any analyzed surface. This nano-faceting, which should not be confused with step bunching, can be considered as a close-to-equilibrium instability, for this reason can be hindered.

Stability of Ultrathin Amorphous Calcium Phosphate Artificial Enamel Sheets under Simulated Intraoral Environment Condition

2019 ◽  
Vol 829 ◽  
pp. 16-20
Author(s):  
Nobuhiro Kato ◽  
Mizuki Hirai ◽  
Ei Yamamoto ◽  
Shigeki Hontsu
Keyword(s):  
Calcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Dental Materials ◽  
Cross Sectional ◽  
Sem Image ◽  
Long Term Stability ◽  
Optical Images ◽  
Surface Morphologies ◽  
Environment Condition

Dental materials purely composed of calcium phosphate are ideal for the dental medicine. We have been developing ultrathin amorphous calcium phosphate (ACP) sheets for enamel repair. In this study, long term stability of the ultrathin ACP sheets applied on enamel surfaces which kept in a simulated intraoral condition for 21 days was evaluated. Surface morphologies of the ACP sheets were observed by optical images. A boundary condition between the ACP sheet and the enamel was evaluated by cross-sectional SEM image. A durability of the ACP sheet was evaluated by a brushing test conducted after 21 days incubation. As the result of these evaluations, it was confirmed that the ACP sheets were stable even after long-term incubation under the simulated intraoral environment condition.

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