Characterization Of Thin Films Research Articles

Preparation, characterization, and electrical properties of PVDF-ZnO nanocomposite thin films

Preparation, characterization, and electrical properties of PVDF-ZnO nanocomposite thin films

Structural characterization of SnS thin films prepared by vacuum evaporation technique

Structural characterization of SnS thin films prepared by vacuum evaporation technique

Synthesis and characterization of ceramic high entropy carbide thin films from the Cr-Hf-Mo-Ta-W refractory metal system

We use reactive DC magnetron sputtering to showcase synthesis strategies for multicomponent carbides with the NaCl-type fcc structure and illustrate how deposition conditions allow controlling the formation of metallic and ceramic single phases in the Cr-Hf-Mo-Ta-W system. The synthesis is performed in argon flow and different acetylene flows from 0 to 12sccm, at ambient and elevated temperatures (700 °C), respectively, hindering/promoting the adatom diffusion. Structural and microstructural investigations reveal the formation of the bcc metallic phase (a=3.188−3.209Å) in films deposited without acetylene flow, also supported by ab initio density function theory (DFT) analysis of lattice parameters as a function of the C content. Experimentally, a bcc-to-fcc phase transition is observed through the formation of an amorphous coating. Contrarily, samples deposited in higher acetylene flow show an fcc multielement carbide phase (a=4.33−4.49 Å). The crystalline films reveal columnar morphology, while the amorphous ones are very dense. We report promising mechanical properties, with hardness up to 25±1GPa. The indentation moduli reach up to 319±6GPa and show trends consistent with DFT predictions. Our study paves the path towards the preparation of Cr-Hf-Mo-Ta-W multicomponent carbides by magnetron sputtering, showing promising microstructure as well as mechanical properties.

Nanostructuring, fractal characterization and wettability of ion irradiated Au thin films and their thickness effect

This study proposes a method for modifying the wettability of Au thin films of thicknesses 5 nm and 10 nm on Si substrates using 8 keV Ne ion beam irradiation at different fluences, thereby enabling surface wettability adjustment at the nano-scale and its thickness dependence. This advancement would be highly beneficial for applications such as high-resolution printing and nano-biotechnology. The contact angle of the irradiated region for the 5 nm thin film changed from hydrophobic to hydrophilic with increasing ion dosage, whereas for the 10 nm thin film, it changed from hydrophilic to hydrophobic under the same conditions. Fractal analysis was performed on pristine and ion beam modified surfaces to investigate the underlying nano-structuring process, with reported values for average roughness (Ra), Hurst exponent (H), fractal dimension (Df), contact angle (CA), and wettability at different ion dosages. Atomic Force Microscopy and Rutherford Backscattering Spectroscopy were used to examine surface roughness and depth profile. The process of sputtering becomes crucial when the ion range approaches the thickness of thin films, with the sputter yield showing dependence on the thickness of thin films at different ion fluence levels. Monte Carlo simulations SRIM/TRIM and TRIDYN were used for comparison with the experimental results, with TRIDYN taking into account dynamic changes in the target's morphology and composition.

Synthesis and Characterization of ZnO-CuO Nanocomposites Thin Film for Optoelectronics Applications

In this work, the spray pyrolysis technique on glass substrates at 480°C was effectively used to generate ZnO, CuO, and n-ZnO/p-CuO nanocomposite thin films. The structure of the ZnO thin films exhibited a hexagonal wurtzite type. In the visible region of the spectrum (400–700 nm), the resulting films had optical transmission ranging from 73% to 83% and optical band gap fluctuations of 3.23 to 3.25 eV. Analysis of the m-lines spectroscopy revealed that the obtained thin layers (ZnO, ZC3, and ZC7) exhibited two modes for both TE and TM polarizations across different molar percentages. This observation confirms the efficacy of the spray pyrolysis deposition technique in producing high-quality waveguides based on ZnO.

Synthesis, characterization, and application of silica aerogel thin films prepared via surface derivatization: A comprehensive study on micro-silica nanofilms for enhanced photoelectric conversion efficiency in photovoltaic solar cells

Silica aerogels are nanoporous materials with exceptional optical and physical properties, making them promising candidates to enhance solar cell efficiency as antireflective coatings. This study synthesized hydrophobic silica aerogel thin films under ambient conditions and characterized their porous structure, surface morphology, and optical performance. The films were deposited on monocrystalline silicon solar cells to assess their impact on photovoltaic properties. A two-step acid/base catalyzed sol-gel process was utilized, followed by solvent exchange and surface modification with trimethylchlorosilane. Structural analysis via SEM revealed successful deposition of crack-free films when aging occurred in an ethanol environment. The aerogel displayed considerable specific surface area (115 m2/g), porosity (77.92%) and surface roughness (55-78%) along with a low refractive index (1.05), benefiting light harvesting. Preliminary solar testing showed increased output voltage with a 0.2 mm aerogel coating versus a bare cell. Further IV measurements demonstrated enhanced charge transport and conversion efficiency for the treated cell. The aerogels antireflective and light-trapping effects appear to improve photon absorption. This initial research validates the potential of ambient pressure-synthesized hydrophobic silica aerogels to increase the performance of silicon photovoltaics cost-effectively. Further optimization of film thickness and morphology could realize higher efficiency gains.

Dynamic wire-pull rubber diaphragm for rapid formation and spatio-temporal investigation of multi-shape free-standing liquid films

Quantitative manufacturing and characterization of thin films are relevant in different scientific and industrial fields. Especially, for the studies of fluid dynamics, the experimental verification of theoretical models creates the need of a free-standing liquid film formation. Driven by the lack of fast and accurate liquid film forming technology, we present a novel device able to fabricate thin free-standing liquid films, which is based on a dynamic and adjustable diaphragm, the opening of which allows for the rapid formation of a self-supported liquid film confined in a wire-pull rubber band. The quantitative thickness mapping of the film formation and its time-resolved evolution are performed by digital holography in real-time. This builds up a strategy that allows for the accurate liquid film formation with controllable size and volume. As the results, multi-shape and multi-material thin films under controllable and stable conditions are successfully formed, including free-standing water, soapy water and glycerol films. A label-free spatio-temporal analysis method for flow dynamics is proposed: The full-field time series of film thickness is reassembled in a new coordinate system composed of radius, time, and thickness. Such spatio-temporal analysis reveals details of leveling and drainage processes. To the best of our knowledge, this is the first full-field quantitative thickness analysis of multi-shape and multi-material thin films. The proposed Dynamic Wire-pull Rubber Diaphragm (DWRD) together with the digital holography add-on offer characterization abilities with an unprecedented level of details allowing for a deeper understanding of the underlying thin film dynamics that can be useful in several different scientific and technological fields as biotechnology, life science, and nanotechnology.

Synthesis and characterization of CZTS and Cu2-xAgxZnSnS4 thin films for the application of solar cells

We report on colloidal Cu2ZnSnS4 (CZTS) and Cu2-xAgxZnSnS4 (X=0.25) nanoparticles synthesis by sol-gel spin coating process and hot injection method. The colloidal nanoparticles were deposited on ITO substrates by using spin-coating techniques. The deposited thin films were characterized by X-ray diffraction (XRD), UV-visible spectrometer, FE-SEM, Raman spectroscopy and Keithley 2450 Source meter. XRD reveals that the crystal structure of CZTS is confirmed tetragonal structure with peak (112) and observed the changes to wurtzite peak (002) due to the presence of Ag. UV visible spectra show that the optical band gap of CZTS nanoparticles decreases from 2 eV to around 1.75 eV, and there is a significant improvement in absorption coefficient when the sample is prepared under a nitrogen atmosphere. FESEM captured the microstructure image of CZTS and Cu2-xAgxZnSnS4. Photoluminescence (PL) reveals the emission peaks and Raman spectra investigate the secondary phases present. XPS confirms the presence of each element and their oxidation state. Further, electrical properties are studied using the four-probe method at room temperature. CZTS offers optical and electrical properties, which allow it to be suitable for thin-film solar cell absorber layers, and Ag doping enhances its properties.

Characterization of Nanocrystalline SnS Thin Film Fabricated used PLD Method for Photodetection Applications

Pulsed laser deposition was used to create tin sulfide (SnS) nanoparticles with a Nd:YAG laser (700 mJ) with laser pulses of (200, 250, 300, and 350 pulses). Nanoparticles were created and investigated using XRD, AFM, and UV-Vis spectroscopy to understand their optical, topographical, and electrical properties. After that, a SnS photodetector was built for the first time, and its performance, photoresponse, and sensitivity were evaluated. The development of monocrystalline SnS films was confirmed by X-ray diffraction (XRD) examination. Clear crystallization with increased crystalline size and the optimum orientation was observed in the sample synthesized SnS thin film treated with 300 pulses. The crystallite size increased from 44 at 200 to 77 nm for 350 pulses. These films were characterized by better surface morphology with (111) preferred crystals. In addition, atomic force microscopy (AFM) studies showed that the average diameter of generated SnS nanoparticles rose from (39.4 nm to 64.7) nm when the laser pulses increased in pulsed laser deposition. Transmission measurements were used to determine the films' absorption coefficient energy gap (Eg), and they showed that the optical transition was direct and that the transmittance value dropped with increasing laser pulses. Band gap energy is reduced from 2.139 to 1.773 eV. Moreover, Hall Effect measurements on all samples demonstrate that all thin films were n-type, with charge carrier concentration increasing with increased pulses and carrier mobility decreasing with increased pulses. The photodetectors ' photosensitivity was evaluated in the dark after depositing Al contacts on SnS thin films through a metal mask. The Pulses of enhancement cause a red shift in the values of particular detectivity and quantum efficiency. The highest responsivity was obtained at 350 pulses, 6.72×10−1 AW−1. The high (QE) of 150% at 200 p and detectivity of 2.9×1011 cm, Hz1/2.W-1 at 300p.

Characterization of NiOAg thin film applicated as photocatalyst for degradation of methylene blue dye waste in Yogyakarta textile factory

Thin films of NiOAg were grown onto glass substrates by radio frequency (RF) sputtering technique at 13.56 MHz RF with variation in oxygen pressure. The research was conducted on preparation and characterization of NiOAg thin films, applicated as a photocatalyst for the degradation of methylene blue. X-ray diffraction analysis showed stronger intensity (111) and (200) planes at peak 2θ of 37.66° and 43.23°. Energy dispersive x-ray analysis showed the following composition: Ni = 40.45%, Ag = 13.01%, and O = 46.53%. Based on UV–vis, it was found that the bandgap energy was 2.8, 3.1, and 3.2 eV for oxygen pressures of 0.05, 0.1, and 0.15 × 10−2 mbar, respectively. From the experiment on the degradation of methylene blue, which was taken from textile factory dye waste in Yogyakarta/Indonesia, the best value of degradation was obtained as 91.96%.

Experimental Techniques for the Characterization of Magnetic Thin Films

This review article describes the various experimental techniques, which are required for the characterization of magnetic thin films. Characterization is an essential process to understand the properties of magnetic thin films. By knowing the properties of these materials, one can utilize them in various technological applications as per requirements. There are different characterization tools to study the different properties of nanostructured materials. Some important experimental techniques employed to characterize the magnetic thin films are: X-Ray Diffraction, X-Ray reflectivity, Field emission scanning electron microscopy, Energy dispersive spectrometer, Transmission electron microscopy, Superconducting quantum interference device, Raman spectroscopy and X-ray absorption spectroscopy etc. These techniques will develop a better understanding of the structural, morphological, and magnetic properties of the materials to the scientific community. The discussion made in the present review article would be extremely helpful to the researchers who are doing research in the various branches of science and engineering.

Optical characterization and dispersion analyses of plasma polymerized methyl acrylate thin films

This work reports the structural characteristics, surface morphology, linear and nonlinear optical properties of 110 to 225 nm thick plasma polymerized methyl acrylate (PPMA) thin films. X-ray diffraction analyses confirm the amorphous nature of the films. Field emission scanning electron micrographs of the films display cluster-based surface morphology. Attenuated total reflectance Fourier transform infrared spectroscopy confirms the chemical structural changes in the films. The optical properties were studied based on the absorbance, transmittance, and reflectance spectra measured by an ultraviolet–visible spectrophotometer within the wavelength ranges from 200 to 800 nm. The direct optical band gap and Urbach values are increased from 3.66 to 3.83 eV and 0.28 to 0.45 eV, respectively with increasing film thickness. The extinction coefficient and refractive index were evaluated, and discussed a correlation between the refractive index and the optical bandgap. The real and imaginary dielectric constants, volume/surface energy loss functions and skin depth were deduced. The oscillator energies and parameters were analyzed using the concept of Wemple-DiDomenico and Sellmeier models, respectively for a single oscillator. Static linear refractive index for the studied films exhibits normal dispersion behavior with film thicknesses and satisfied Moss, Ravindra-Gupta, and Herve-Vandamme rules. The linear susceptibility, third-order nonlinear susceptibility and the non-linear refractive index are considerably reduced from 0.20, 29.5 × 10−14 esu, and 5.89 × 10−12 esu with increasing optical band gap energies. The outcomes from the analyses of PPMA demonstrated their potential for usage in electronic, optoelectronic, and non-linear device applications.

Synthesis, Characterization and Power Factor Estimation of SnSe Thin Film for Energy Harvesting Applications

In this work, a simple, cost-effective successive ionic layer adsorption and reaction (SILAR) deposition technique has been used to deposit a high-quality tin selenide (SnSe) thin film onto a glass substrate. Structural, morphologic, and thermoelectric properties have been characterized for the prepared thin film. X-ray diffraction (XRD) results of the SnSe thin film reveal an orthorhombic structure phase. The morphological properties of the prepared thin films have been studied using field emission scanning electron microscopy (FESEM). The stoichiometric composition of the deposited thin film and the elemental binding energies of the Sn and Se elements have been investigated with energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The Fourier transformation infrared (FTIR) spectrum of the SnSe thin film displays vibrational modes of chalcogenides bonds. These results suggest that the developed thin film is crystalline, uniform, and without impurities and is appropriate for energy harvesting applications. The prepared thin film’s Seebeck coefficient and electrical resistivity were estimated through ZEM-3 from room temperature to 600 K. The power factor was evaluated. A substantially high electrical conductivity is observed, which decreases somewhat with temperature, suggesting a semimetal conducting transport—the absolute values of the Seebeck coefficient increase with temperature. The resulting power factor showed the highest values near room temperature and a somewhat decreasing trend as the temperature increased. Despite lower values of the Seebeck coefficient, the substantially enhanced power factor is due to the higher electrical conductivity of the thin film, superior to that reported previously. This precursor study demonstrates promising results for developing high-performance flexible thermoelectric devices via a simple and facile SILAR strategy.

Effect of annealing temperature on the structure and dielectric characterization of ITO thin films on a boro-float substrate prepared by radio frequency sputtering

Effect of annealing temperature on the structure and dielectric characterization of ITO thin films on a boro-float substrate prepared by radio frequency sputtering

Effect of annealing temperature on bismuth vanadate nano thin films for solar cell applications

Bismuth vanadate (BiVO4) has been used as the photoanode electrodes in ferroelectric solar cells owing to its unique combination of properties: a narrow bandgap among ferroelectrics, economic viability, negative conduction band edge, and remarkable stability. The present work explores the fabrication and characterization of BiVO4 thin films prepared via spin coating, with a specific focus on elucidating the influence of the annealing temperature (400–550 °C) on their structural, optical, and photovoltaic properties. From X-ray diffraction (XRD) analysis, it is observed that higher annealing temperatures have promoted the formation of larger grains, enhanced crystallinity, and induced a preferred crystal orientation characteristic of the monoclinic scheelite structure. Tauc plot analysis shows the dependence of the optical band gap on the annealing temperature for BiVO4 thin films. The band gap values have decreased slightly from 2.50 eV at 400 °C to 2.44 eV at 550 °C. This is indicated by the slightly narrowed bandgap, which influences the structure of the material or defect states at higher annealing temperatures. A narrower bandgap allows for the absorption of lower-energy light, potentially improving the light absorption efficiency of BiVO4 thin films in photoanode applications. The influence of annealing temperature on BiVO₄ thin film solar cell performance was investigated further through the analysis of open-circuit voltage (Voc), short-circuit current (Isc) and power conversion efficiency.

Crystal growth characterization of WSe2 thin film using machine learning

Materials characterization remains a labor-intensive process, with a large amount of expert time required to post-process and analyze micrographs. As a result, machine learning has become an essential tool in materials science, including for materials characterization. In this study, we perform an in-depth analysis of the prediction of crystal coverage in WSe2 thin film atomic force microscopy (AFM) height maps with supervised regression and segmentation models. Regression models were trained from scratch and through transfer learning from a ResNet pretrained on ImageNet and MicroNet to predict monolayer crystal coverage. Models trained from scratch outperformed those using features extracted from pretrained models, but fine-tuning yielded the best performance, with an impressive 0.99 R2 value on a diverse set of held-out test micrographs. Notably, features extracted from MicroNet showed significantly better performance than those from ImageNet, but fine-tuning on ImageNet demonstrated the reverse. As the problem is natively a segmentation task, the segmentation models excelled in determining crystal coverage on image patches. However, when applied to full images rather than patches, the performance of segmentation models degraded considerably, while the regressors did not, suggesting that regression models may be more robust to scale and dimension changes compared to segmentation models. Our results demonstrate the efficacy of computer vision models for automating sample characterization in 2D materials while providing important practical considerations for their use in the development of chalcogenide thin films.

Growth and characterization of rubidium titanyl phosphate thin films by pulsed laser deposition

The mm2 orthorhombic potassium titanyl phosphate crystal, i.e. KTiOPO4 (KTP), is a famous biaxial nonlinear optical crystal widely used commercially for second harmonic generation (SHG) or optical parametric oscillation (OPO) pumped by a 1.064 μm Nd:YAG laser for example. Most of its applications are based on bulk single KTP crystals. However, there is a strong interest to elaborate submicrometric waveguides in the framework of integrated photonic device. Such waveguides could be a serious alternative to efficient low energy nonlinear optical devices in particular for Telecom or spectroscopic applications.PLD is a technique particularly well suited for growing single oxides films with complex chemical composition. This technique consists in a high energy laser ablation of a material with the same chemical composition than that of the desired layer. The plasma of the ablated material is then condensed on the substrate and heated to a temperature such as the aggregates can self-organize on the atomic lattice of the substrate leading to the epitaxial layer.In this study, we performed epitaxial growth of the RbTiOPO4 (RTP) phase on KTP single crystals by PLD. The target that has been used was a single RTP crystal. However, by chemical analysis and XRay diffraction we demonstrated that due to alkali interdiffusion between film and substrate, it was not possible to achieve a pure layer of RTP but most likely an mixed stoichiometry KxRb(1-x) TiOPO4 but still in epitaxy.

Characterization of MoO3 and TixMoyOz Thin Films Prepared by Atomic Layer Deposition

Characterization of MoO3 and TixMoyOz Thin Films Prepared by Atomic Layer Deposition

Synthesis, Characterization and Functionalization of P3HT-CNT Nanocomposite Thin Films with Doped Ag2O

Synthesis, Characterization and Functionalization of P3HT-CNT Nanocomposite Thin Films with Doped Ag2O

Optical and structural characterization of zinc oxide thin films upon ion beam assisted smoothing

Wurtzite zinc oxide (ZnO) has a preferential growth direction along the c-axis of the hexagonal unit cell, which, especially in combination with underlying (amorphous) heterostructures, can lead to a high surface roughness for the ZnO layers. This poses a significant challenge to the construction of e.g. photonic waveguides or gratings. Here, we propose an efficient way for smoothing ZnO surfaces after deposition using a collimated beam of Argon ions. Furthermore, the influence of this treatment at different angles of incidence and fluence of the ions on the morphological, structural and linear optical emission properties is investigated using atomic force microscopy, X-ray diffraction, spectroscopic ellipsometry and photoluminescence (PL) experiments. Our results suggest that using an ion beam incident at an angle of 85° reduces the surface roughness by around 70% while keeping the ZnO crystal structure intact. Though such a treatment leads to a reduced intensity and to a broadening of the PL-emission, excitonic transitions are still prominently observable.