Surface Antireflection of Transparent Electromagnetic Shielding Films of Different Thicknesses

Electromagnetic interference protection in optoelectronic devices is challenging because of the dual requirements of optical transmittance and high shielding effectiveness (SE). Herein, we propose a novel silver nanowire (AgNW)/polyethylene terephthalate (PET) multi-layer mesh pattern structure for transparent electromagnetic shielding obtained via laser marking and transfer printing. A three-layer composite shielding film with an optical transmittance of 67.8% exhibits a SE of 44 dB at 10 GHz, which is superior to most of the reported transparent shielding films composed of AgNWs to date. The newly designed multi-layer composite structure can enhance the transparent shielding properties of the shielding film via optimization of the AgNW distribution and the shielding film structure. It is expected that this multi-layer mesh composite structure will have splendid application prospects in electromagnetic shielding films, which require both light transmittance and high SE.

Molybdenum oxide ( $${\text {MoO}}_3$$ ) is a chromogenic and a wide band gap n-type semiconductor. Thickness of thin films is usually observed to have significant influence on various properties of chromogenic materials. $${\text {MoO}}_3$$ thin films of different thicknesses (100 nm, 200 nm and 400 nm) were deposited on glass substrates by thermal evaporation technique. The effect of thickness of deposited thin films on the structural, morphological and optical properties was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM) and UV–visible spectroscopy. XRD analysis revealed the amorphous nature of deposited thin films of different thicknesses. FTIR spectrum showed the characteristic vibrations of intermolecular bonds in molybdenum oxide. The surface morphology of $${\text {MoO}}_3$$ films showed nanoflakes like structures which became densely stacked with increase in film thickness and transformed to large grains with uniform coverage of the substrate surface with randomly oriented morphology. The transmission spectra revealed the slight increase in average transmittance in the visible-NIR region with increase in thickness of thin films. The optical band gap of the deposited thin films of different thicknesses was found to be increasing with increase in thickness of the films which may be attributed to decreased defect centres. The decrease in the values of Urbach energy with increase in thickness may be due to the increased homogeneity and decrease in scattering centres.

The depth‐dependent chemical constitution of Ti51Ni38Cu11 thin films of different total film thickness from 400 to 50 nm was characterized using X‐ray photoelectron spectroscopy (XPS). It was analyzed how reaction layers, which form on the surface of the film significantly change the chemical composition of the transforming phase, which leads in turn to altered phase transformation properties. For thinner films, the deviation from the nominal chemical composition increases. For a film thickness of 50 nm, a Ti loss of ≈9 at% is observed. The Ni content is increased by ≈5 at%, whereas the Cu content stays relatively constant for films of different thickness. The results are summarized in a layer model, which supports designing nanoscale shape memory thin films.

The effect of thickness on the properties of solution-deposited LiMn 2O 4 thin films

The efficient electrocatalysts for direct methanol oxidation play an essential role in the electrochemical energy conversion systems for their application in a wide range of portable applications. Consequently, Cu-doped NiO thin films on fluorine-doped tin oxide (FTO) were successfully prepared by the co-sputtering deposition technique, using various deposition times (300, 600, 900, and 1200 seconds), and producing films of different thicknesses (30, 55, 90, and 120 nm, respectively). X-ray diffraction (XRD) revealed the ideal crystallinity of the structure of the prepared films and was used to observe the effect of the thickness of the films on the crystal size. Energy-dispersive X-ray spectroscopy (EDS) confirmed the purity of the deposited film without any contamination. Field emission scanning electron microscopy (FESEM) images confirmed the film thickness increase with increasing deposition time. The surface roughness value of the Cu–NiO 1200 film was found to be 3.2 nm based on the atomic force microscopy (AFM) measurements. The deposited thin films of different thicknesses have been used as electrocatalysts for methanol oxidation at various concentrations of methanol (0, 0.5, 1, and 2 M), and displayed the highest electrocatalytic performance in 1 M methanol. Cu-doped NiO thin films have the advantage as electrocatalysts where they can be used directly without adding any binder or conducting agents, this is because Cu-doped NiO is deposited with high adhesion and strong electrical contact to the FTO substrate. A clear impact on the catalytic activity with increasing film thickness and a correlation between the film thickness and its catalytic activity was observed. The current density increased by about 60% for the Cu–NiO 1200 sample compared to Cu–NiO 300 sample, with the lowest onset potential of 0.4 V vs. Ag/AgCl. All deposited thin films of different thicknesses exhibited high stability at 0.6 V in 1 M methanol. This will open the window toward using physical deposition techniques for optimizing the electrocatalytic activity of different catalysts for electrocatalytic applications.

Thickness dependent structural, electrical and optical properties of cubic SnS thin films

Thin films of different thicknesses were prepared through glow discharge of 2‐(diethylamino)ethyl methacrylate (DEAEMA) using a capacitively coupled reactor. Current density–voltage (J–V) characteristics for plasma polymerized (PP) DEAEMA thin films of thicknesses 100, 200, 250, and 300 nm in aluminum/PPDEAEMA/aluminum sandwich configuration were studied over the temperature range from 298 to 423 K. J–V curves reveal that in the low‐voltage region, the conduction current obeys Ohm's law while in the high‐voltage region the behavior attributed to be space charge‐limited conduction in PPDEAEMA thin films. The carrier mobility was calculated to be about 6.80 × 10−19 to 2.38 × 10−18 m−2 V−1s−1 for various thicknesses. The free carrier density was found to be about 1.78 × 1023 to 2.04 × 1023 m−3, and the trap density was found to be about 6.93 × 1023 to 15.9 × 1023 m−3 for different thicknesses. The activation energies were estimated to be about 0.005–0.016 eV for 2 and 30 V of PPDEAEMA thin films of different thicknesses. The low‐activation energies indicate that the thermally activated hopping conduction is operative in PPDEAEMA thin films. POLYM. ENG. SCI., 55:2729–2734, 2015. © 2015 Society of Plastics Engineers

A comparative study on the nature of direct current electrical conduction in the monolayer and bilayer plasma polymerized thin films has been discussed in this article. The plasma polymerized pyrrole (PPPy) monolayer, plasma polymerized N,N,3,5-tetramethylaniline (PPTMA) monolayer and plasma polymerized pyrrole-N,N,3,5-tetramethylaniline (PPPy-PPTMA) bilayer thin films were deposited at room temperature onto glass substrates by using a parallel plate capacitively coupled glow discharge reactor. The current density-voltage (J-V) characteristics and the conductivity-voltage (σ-V) characteristics have been studied to analyze the direct current conduction mechanism in PPPy, PPTMA monolayer and PPPy-PPTMA bilayer thin films. The observed results have been presented in this paper. The J-V and σ-V characteristics of PPPy and PPTMA monolayer thin films of different thicknesses indicated an increase in electrical conduction and also an increase in conductivity in the films of lower thicknesses. It is also observed that PPTMA thin films are more conductive than that of PPPy thin films. As a result the PPPy-PPTMA bilayer thin films of different thicknesses and different deposition time ratios indicated an increase in conductivity as the proportion of PPTMA is increased in the films. In addition to that, from the J-V and σ-V characteristics of PPPy, PPTMA and PPPy-PPTMA thin films of same thickness, it is observed that the current conduction and the conductivity in the bilayer thin films is less compared to the monolayer thin films. This unusual result has been explained by studying ideal and real bilayer thin films. It is also seen that in the low voltage region, the current conduction obeys Ohm’s law while the charge transport phenomenon appears to be the space charge limited conduction (SCLC) in the higher voltage regions.

Microstructural parameters and optical constants of ZnTe thin films with various thicknesses

Measurement of plane stress essential work of fracture (EWF) for polymer films: effects of gripping and notching methodology

Inhibition of the corrosion of stainless steel by poly-N-vinylimidazole and N-vinylimidazole

Time dependent electrical resistance of Bi 2(Te 0.4Se 0.6) 3 thin films in vacuum and on exposure to atmosphere

In this work, Bi2O3 was deposited as a thin film of different thickness (400, 500, and 600 ±20 nm) by using thermal oxidation at 573 K with ambient oxygen of evaporated bismuth (Bi) thin films in a vacuum on glass substrate and on Si wafer to produce n-Bi2O3/p-Si heterojunction. The effect of thickness on the structural, electrical, surface and optical properties of Bi2O3 thin films was studied. XRD analysis reveals that all the as deposited Bi2O3 films show polycrystalline tetragonal structure, with preferential orientation in the (201) direction, without any change in structure due to increase of film thickness. AFM and SEM images are used to investigate the influences of film thickness on surface properties. The optical measurement were taken for the wave length range (400-1100) nm showed that the nature of the optical transition has been direct allowed with average band gap energies varies in the range of (2.9-2.25) eV with change thickness parameter. The extent and nature of transmittance, absorbance, reflectance and optimized band gap of the material assure to utilize it for photovoltaic applications. Hall measurements showed that all the films are n-type. The electrical properties of n-Bi2O3/p-Si heterojunction (HJ) were obtained by I-V (dark and illuminated) and C-V measurement at frequency (10 MHz) at different thickness. The ideality factor saturation current density, depletion width, built-in potential and carrier concentration are characterized under different thickness. The results show these HJ were of abrupt type. The photovoltaic measurements short-circuit current density, open-circuit voltage, fill factor and efficiencies are determined for all samples. Finally thermal oxidation allowed fabrication n-Bi2O3/p-Si heterojunction with different thickness for solar cell application.In this work, Bi2O3 was deposited as a thin film of different thickness (400, 500, and 600 ±20 nm) by using thermal oxidation at 573 K with ambient oxygen of evaporated bismuth (Bi) thin films in a vacuum on glass substrate and on Si wafer to produce n-Bi2O3/p-Si heterojunction. The effect of thickness on the structural, electrical, surface and optical properties of Bi2O3 thin films was studied. XRD analysis reveals that all the as deposited Bi2O3 films show polycrystalline tetragonal structure, with preferential orientation in the (201) direction, without any change in structure due to increase of film thickness. AFM and SEM images are used to investigate the influences of film thickness on surface properties. The optical measurement were taken for the wave length range (400-1100) nm showed that the nature of the optical transition has been direct allowed with average band gap energies varies in the range of (2.9-2.25) eV with change thickness parameter. The extent and nature of transmittance, absorbance...

Effect of film thickness on the temperature dependence of thermal conductivity for diamond/BeO composites

Unveiling the nature of adsorbed species onto the surface of MgO thin films during prolonged annealing