Characterization Of Films Research Articles

Surface enhanced Raman scattering in thin films: the importance of Raman analyte-plasmonic particle inverse geometry

Most of the successful applications of surface enhanced Raman scattering (SERS) involves placing the Raman analyte molecule over the SERS substrate. This conventional geometry of SERS does not work when the Raman analyte is in the form of a thin film. In this report, we experimentally demonstrate the importance of the rarely explored inverse geometry wherein a plasmonic particle is placed over an analyte thin film for SERS study. Initially, as a case study, the effect of size, concentration, and distribution of gold nanoparticles (AuNPs) on the SERS of Si wafer was performed. The AuNPs, prepared by optimized annealing of direct current sputtered Au, were characterized by scanning electron microscopy, atomic force microscopy, and UV-Visible spectrophotometry. Finally, as an application, SERS in inverse geometry was successfully performed with an electron-beam evaporated Si thin film. For the first time, a working formula has been proposed to determine the experimental enhancement factor (EEF) for the inverse geometry of SERS. The values of EEF were estimated to be 1526 and 3274 respectively for Si wafer and Si thin film for the similar distribution of AuNPs of average size 52 nm. This study provides an insight into the characterization of thin films.

Comprehensive Characterization of Gelatin-Pullulan Blend Films Incorporated with Bacteriophages: Assessing Physicochemical, Mechanical, Optical, Thermal, and Antimicrobial Properties

Comprehensive Characterization of Gelatin-Pullulan Blend Films Incorporated with Bacteriophages: Assessing Physicochemical, Mechanical, Optical, Thermal, and Antimicrobial Properties

Fabrication, Structural Characterization, Dielectric Analysis and Thermal Properties of Novel Flexible Polymer Composite Films

Abstract The films were characterized by different methods as FTIR, SEM, XRD and TGA to prove the efficient manufacturing of the composite. The dielectric performance measurements were done at frequency of 20 Hz to 6 MHz for the polymer PET and the composite (PPy-Fe2O3)/PET with varying concentrations of Fe2O3. Moreover, to reveal the characteristics of the fabricated composite, the contact angle, the work of adhesion, surface energy of the composite PET/(PPy-Fe2O3) films were considerably determined. The SEM results support the deposition of PPy-Fe2O3 composite on the PET surface. The water contact angle drops from 78.32 o for PET to 40.11o for PET/6%(PPy-Fe2O3), while the dispersive free energy raised from 23.9 mJ/m2 to 43.7 mJ/m2and the polar free energy rises from 8.9 mJ/m2 to 22.3 mJ/m2. The concentration of Fe2O3 increased the surface features of the samples, according to the obtained results. At frequency of 100 Hz, the dielectric constant enhanced from 18 for PET to 923 for the PET/6%(PPy-Fe2O3), and the dielectric loss improved from 24 to 9231, while the energy density improved fromm 7.9x10-5 J/m3 for PET to 408x10-5 J/m3. The TGA results show marginal modifications in thermal stability after deposition the PPy/Fe2O3 on the PET film.

Synthesis and characterization of Cr-doped cadmium oxide thin films for NH3 gas-sensing applications

Synthesis and characterization of Cr-doped cadmium oxide thin films for NH3 gas-sensing applications

Thickness effects on the physical characterization of nanostructured CuO thin films for hydrogen gas sensor

In these studies, radio frequency (RF) magnetron sputtering was used to produce nanostructured CuO thin films on glass bases with different thicknesses of (250, 300, and 350 nm). X-ray diffraction (XRD) analysis of these films revealed a polycrystalline structure with a preferred peak along the (111) plane. The Scherrer formula was used to compute the grain size. It was found that the average grain sizes are 10.78 nm, 11.36 nm, and 11.84 nm for film thicknesses of 250, 3000, and 300 nm, respectively, while the dislocation density and strain values decline. The surface roughness decreased from 9.30 nm to 4.71 nm as the thickness increased, according to atomic force microscopy (AFM) data. As the thickness of the film grew, the root mean square (RMS) roughness likewise decreased from 9.18 nm to 4.29 nm. The homogenous, semi-spherical structure comprises uniformly distributed particles, as demonstrated by SEM images. The optical properties of the grown films showed that the absorption coefficient considerably increased with film thickness. Transmittance, band gap, refractive index, and extinction coefficient all decrease with increasing film thickness. The hydrogen gas measurements, indicated a reduction in sensitivity as the thickness and gas concentration increased at 30°C.

Epitaxial growth, structural and magnetic characterization of thulium thin films

Epitaxial growth, structural and magnetic characterization of thulium thin films

Optical characterization of high-quality spin-Coated PVA nanostructured films for photo-sensing application

In our investigation, we fabricated high-quality Polyvinyl Alcohol (PVA) films via spin coating on a variety of substrates, with a focus on their potential applications in diverse devices. Through comprehensive characterization techniques, including spectrophotometer measurements, we evaluated the nanostructure and quality of these films. Our analysis revealed a distinct energy gap of 1.74 eV and a significant 5.37 eV direct allowed optical transition, shedding light on the correlation between absorption coefficient and photon energy. Additionally, we meticulously calculated dispersion parameters using the Wemple-DiDomenico relation, obtaining values of 19.1 eV for dispersion energy and 9.48 eV for oscillator energy under the single oscillator model. These results provide further validation of the unique structural characteristics of PVA films. Importantly, our findings underscore the potential of these materials for advanced optoelectronic devices, particularly in the realm of photosensor applications.

Characterization of nanocomposite films based on tomato seed mucilage, gelatin and TiO2 nanoparticles

The aim of the present research was to investigate the interaction effect of incorporating titanium dioxide (TiO2) (0 %, 0.5 %, and 1 %) nanoparticles and manipulating the proportion of tomato seed mucilage (TSM) and gelatin (Ge) (1: 0, 0.33:0.67, 0.67:0.33, and 0:1) on the physical, mechanical, and microbial characteristics of the film. The findings indicated that the incorporation of TiO2 engendered an augmentation in the surface roughness of the film and an elevation in the film's thickness. The mechanical evaluation results revealed that the incorporation of TiO2 into the TSM-Ge films significantly enhanced (p˂0.05) the tensile strength (TS), (up to 300 %), an elevation of Young's modulus, while concurrently leading to a reduction in the elongation at break (EB). The incorporation of TiO2 resulted in a significant enhancement in various properties of the film (p˂0.05), including opacity, contact angle, oxygen permeability (OP), water vapor permeability (WVP), moisture absorption, moisture content, solubility, and swelling. The rise in the proportion of TSM resulted in a concomitant increase in the color differences (ΔE), and yellowness index (YI). Conversely, there was a decrease in the lightness (L*) and the whiteness index (WI). Additionally, an increase was found in opacity, solubility, moisture content, WVP, OP, swelling, and moisture absorption. It was observed that films without TiO2 exhibited no inhibitory effect. However, upon augmenting the concentration of TiO2 to 1 %, notable inhibitory and lethal effects were observed against various microorganisms, including Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida glabrata. The results showed that the TSM-Ge composite film containing TiO2, exhibited potential as a viable choice for food packaging susceptible to microbial spoilage.

Single-Walled Carbon Nanotube-Modified Gold Leaf Immunosensor for Escherichia coli Detection.

The requirement to prevent foodborne illnesses underscores the need for reliable detection tools, stimulating biosensor technology with practical solutions for in-field applications. This study introduces a low-cost immunosensor based on a single-walled carbon nanotube (SWCNT)-modified gold leaf electrode (GLE) for the sensitive detection of Escherichia coli. The immunosensor is realized with a layer-by-layer (LbL) assembly technique, creating an electrostatic bond between positively charged polyethylenimine (PEI) and negatively charged carboxyl-functionalized SWCNTs on the GLE. The structural and functional characterization of the PEI-SWCNT film was performed with Raman spectroscopy, high-resolution scanning electron microscopy (HRSEM), and electrical measurements. The PEI-SWCNT film was used as a substrate for antibody immobilization, and the electrochemical sensing potential was validated using electrochemical impedance spectroscopy (EIS). The results showed a wide dynamic range of E. coli detection, 101-108 cfu/mL, with a limit of detection (LOD) of 1.6 cfu/mL in buffer and 15 cfu/mL in the aqueous solution used for cleansing fresh lettuce leaves, affirming its efficiency as a practical and affordable tool in enhancing food safety.

Use of Particle Induced X-Ray Emission (PIXE), Particle Induced Gamma–Ray Emission (PIGE), Energy Dispersive X-Ray Analysis (EDXRF) for Detecting Trace Elements in Soil Sample

This review paper provides a comprehensive overview of trace element analysis utilizing ion-atom interaction techniques, focusing on the principles, applications, and recent advancements in the field. Ion- atom interaction techniques, including Particle Induced X- Ray Emission (PIXE), Particle Induced Gamma–Ray Emission (PIGE), Energy Dispersive X-Ray Analysis (EDXRF), Rutherford backscattering spectroscopy (RBS), and ion beam analysis (IBA), offer unique capabilities for trace element analysis with high sensitivity and minimal sample preparation requirements. The paper begins by discussing the fundamental principles underlying ion-atom interaction techniques, such as the interaction of energetic ions with matter and the subsequent detection of emitted X-rays or backscattered particles. It explores the various analytical parameters that influence the sensitivity, resolution, and depth profiling capabilities of these techniques. Furthermore, the review highlights the diverse applications of ion-atom interaction techniques in fields such as environmental monitoring, forensic science, biomedical research, and materials science. It showcases how these techniques have been utilized to address specific analytical challenges, such as the detection of trace contaminants in environmental samples or the characterization of thin films and semiconductor materials.

Physicochemical and thermal characterization of the edible shellac films incorporated with oleic acid to enhance flexibility, water barrier and retard aging

In this work, shellac plasticized with oleic acid was solvent cast to prepare the flexible and water-resistant film for packaging applications. The films were prepared with varying amounts of oleic acid and studied in detail for appearance, surface morphology, thermal, chemical, barrier, mechanical, and robustness. The surface morphology confirmed the smooth surface of films up to SH-OA20 (100:20 w/w; shellac: oleic acid). Fourier-transform infrared spectroscopy confirmed that oleic acid reduced the hydrogen bonding of the shellac matrix to provide a plasticization effect. Also, the thermal analysis showed a reduction in the melting enthalpy. Moreover, the plasticized films had a better barrier to water vapor due to increased smoothness and reduction in brittleness. Adding oleic acid also increased the elongation at break up to 40 % without any changes in tensile strength. The flexibility of the films increased with the oleic acid content, making them resistant to burst, crumbling, bending, rolling, and stretching. Oleic acid also showed the retardation of aging and thermal aging of shellac. In the future, the long-term stability and migration of the films can be investigated.

A high-resolution characterization of surface film formed on alloys 800 and 690 exposed to chloride and thiosulfate-containing solution at 300°C

Purpose This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C. Design/methodology/approach Alloy 800 and 690 were immersed in chloride and thiosulfate-containing solution at 300°C up to five days, and then the surface film was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometers (EDX). Findings Through static immersion experiments in a high-temperature and high-pressure water environment, the alloy samples covered by surface film after five days of immersion were obtained. The morphology of the surface film was characterized at both horizontal and cross-sectional scales using SEM and focused ion beam-TEM techniques. It was observed that due to the influence of the quartz lining, the surface film primarily exhibited a bilayered structure. The first layer contained a significant amount of SiO2, with a higher content of metal hydroxides compared to metal oxides. The second layer was predominantly composed of Fe, Ni and Cr, with a higher content of metal oxides compared to metal hydroxides. Originality/value The results showed that the materials of the lining of the autoclave could significantly influence the film composition of the tested material, which should be paid attention when analyzing the corrosion mechanism at high temperature.

Fabrication and Characterization of Boron-Implanted Silicon Superconducting Thin Films on SOI Substrates for Low-Temperature Detectors

Fabrication and Characterization of Boron-Implanted Silicon Superconducting Thin Films on SOI Substrates for Low-Temperature Detectors

Thin-film microbattery fabrication by PLD: a comprehensive mini-review

This mini-review reports the latest results on Pulsed Laser Deposition (PLD) for the design and development of microbatteries. Advances in the deposition of thin films for cathodes, anodes and electrolytes are considered separately, the focus being on studies reporting the electrochemical characterization and performance of electroactive films. Some results on the positive effects of coatings to study and mitigate anode degradation are also discussed.

Mechanics manipulation in large-area organic solar modules achieving over 16.5 % efficiency

High-efficiency organic solar cells (OSCs) are typically produced through spin-coating, restricting their application to small areas. Blade-coating, however, emerging as a promising method for large-scale production, yet faces challenges in film morphology optimization, which often leads to reduced power conversion efficiency (PCE). This study delves into the influence of both liquid and solid additives on the morphology of active layer in blade-coated OSCs, comparing them with spin-coated counterparts, using the high-efficiency PM6:D18:BTP-eC9 active layer. For the first time, we discovered the distinct impacts of solid versus liquid additives on the film uniformity, phase separation and crystalline regulation in blade-coating technique. Our findings reveal that liquid additives in blade-coating trigger outward Marangoni flow, causing undesirable material aggregation and phase separation, thereby impairing device performances. Conversely, switching to solid additives, like 1,4-Diiodobenzene (DIB), prevents these detrimental changes in fluid mechanics and preserves the desired additive effects. We demonstrate that solid additives can significantly change these inferior behaviors introduced by liquid additives in blade-coating, regulate phase separation, enhance π-π accumulation and delay crystallization, and ultimately boost OSC efficiency. Using DIB solid additive, we achieved a PCE of 18.81 % in blade-coated devices. Scaling up by 252 times, the PCE of large-area OSC module (15.64 cm²) sustained at 16.70 % (certified 16.66 %), ranking among the highest efficiency for OSC modules reported so far. These modules also exhibited exceptional storage stability, retaining 98 % efficiency after 5880 h in a nitrogen atmosphere. This research also provides a comprehensive understanding from various film characterizations and the perspective of fluid mechanics normally lack in the research. This research not only establishes a new framework for high-performance and large-area OSC modules but also extends its findings to other OSC systems with different additives, demonstrating a roll-to-roll compatible technique.

Influence of light and humidity on the synthesis and characterization of perovskite FAPbI3 thin films

Influence of light and humidity on the synthesis and characterization of perovskite FAPbI3 thin films

Preparation, characterization, and application of pH-responsive biodegradable intelligent indicator film based on rose anthocyanins

An intelligent pH-responsive indicator film (CA/CMC/RA) was fabricated by blending carrageenan (CA), carboxymethylcellulose (CMC), and rose anthocyanin (RA). Fourier transform infrared spectroscopy revealed the formation of hydrogen bonds between CA/CMC and RA. X-ray diffraction analysis demonstrated that the addition of RA enhanced the crystallinity of CA/CMC films. The incorporation of RA altered the microstructure of CA/CMC composite films, resulting in a roughened surface. RA improved the a*, b*, thickness, opacity, and water vapor permeability of CA/CMC/RA films. Moreover, the addition of RA increased the elongation at break, while decreasing the tensile strength. RA significantly increased the antioxidant capacity of CA/CMC films. Furthermore, CA/CMC/RA films exhibited pH-responsiveness, showcasing distinct color changes in different buffer solutions. In the application test, the CA/CMC/RA indicator film was used as a label to monitor the freshness of the ribbon fish stored at 4 °C. The results indicated that the film's color changed from pink to yellow upon spoilage. The observations were consistent with the TVB-N value, which exceeded the set limit (30 mg/100g). Hence, the novel indicator film can serve as a food freshness indicator material.

HiPIMS and Bipolar HiPIMS Techniques for Tunable Phase Formation of Yttrium Oxide Thin Films at Low-Temperature

This study investigates the deposition process and characterization of yttrium oxide thin films using high-power impulse magnetron sputtering (HiPIMS) and bipolar HiPIMS, which are advanced deposition technologies that can effectively use high energy for controlling energy flux to produce thin films. These two techniques require no heat for the control of phase formation of yttrium oxide thin films. The properties of the films were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, ultraviolet–visible spectrometry, and water contact angle analyses. The results indicated that the energy of sputtered species can be effectively tuned by adjusting the process parameters, and it can then be used to achieve phase control of yttrium oxide thin films. The monoclinic phase is associated with a high number of oxygen vacancies in the films. The cubic phase with low oxygen vacancies produces more compact thin films with wide bandgaps. Therefore, the relationship between the process parameters and the resultant structural, morphological, and optical properties as well as the wettability of the deposited films is confirmed. This allows the film properties to be tuned to each application, enabling their use in various fields.

Characterization of columnar BiFeO3 thick films prepared by magnetic field-assisted pulsed laser deposition

Polycrystalline BiFeO3 thick films were prepared on Pt/TiO2/SiO2/Si substates by using magnetic field-assisted pulsed laser deposition. Columnar BiFeO3 thick films were successfully obtained with a thickness of 1.8 μm, owing to an oblique incoming flux and high deposition rate by the confinement of the plume under a magnetic field. In the columnar BiFeO3 thick films, a saturated P-E hysteresis loop was obtained at RT, and the remanent polarization (P r ) and coercive field (E c ) were 42 μC cm−2 and 380 kV cm−1, respectively. Also, the piezoelectric response measured by atomic force microscopy showed a butterfly-shaped curve, and the piezoelectric d 33 coefficient was about 50 pm V−1.

Fabrication and characterization of HfxAl(1-x)Oy ceramic targets and thin films by RF sputtering

The potential of HfO2 as a memory semiconductor material with ferroelectric properties in thin-film deposition has been recently analyzed. In this study, the preparation, composition, and physical properties of Al-doped hafnium oxides were analyzed. HfxAl(1-x)Oy (HAO) [x = 0.33, 0.5, and 0.67] powders were prepared by controlling the ratio of Hf to Al and using ball milling. The HAO powder was calcined at 1000 °C in a furnace and then sintered in a temperature range of 1000–1600 °C by a solid-state reaction method to fabricate high-quality targets with high densities. The density and crystal size increased with the sintering temperature. The 1600-°C Hf0.67Al0.33Oy target was optimal for thin-film deposition. In addition, the target properties were affected by an increase in the HfO2 content x. The crystal structures and sizes, surface free energies, contact angles, and band gaps of the HAOs were evaluated to analyze their potential as high-k dielectric materials. HAO is a promising high-k dielectric and memory material, valuable for further studies on ferroelectric gate oxide materials. This study contributes to the increasing number of studies on the ferroelectricity of HfO2 thin films and provides a fundamental understanding of this material and its potential for novel device applications.