Dielectric Gap Research Articles

Modelling of insulating potential in ultra-thin (42 å) silicon oxide film

Based on previously conducted measurements of the tunneling current-voltage characteristics of metal-SiO2-Si (MOS) structures, modeling of the insulating potential in an ultra-thin (4.2 nm) silicon oxide film was performed. The potential in the dielectric was defined in the shape of a trapezoid, with the lateral slopes simulating transition layers and the top base representing the bulk of SiO2. The model parameters – the barrier height and the coordinates of the trapezoid's corner points – were calculated to achieve the maximum match between the experimental and theoretical voltage derivatives of the current logarithm. Common features of the insulating potential, similar to those in thinner silicon oxide films (3.7 nm), were identified: the barrier occupies up to half of the nominal volume of the dielectric gap and is shifted towards the gate electrode, with its slope towards the semiconductor substrate being much more gradual compared to the slope adjacent to the gate.

Comparative Analysis of Two Different MIM Configurations of a Plasmonic Nanoantenna

AbstractTwo plasmonic nanoantenna configurations—nanodisk and nanostrip arrays—in a metal–insulator-metal (MIM) setup were proposed, optimized, and compared by simulating their optical properties in three-dimensional models using COMSOL Multiphysics software. The optical responses, including electric field enhancement, absorption, reflection, and transmission spectra, were systematically investigated. Optimized geometrical parameters led to a significant enhancement of the electric field within the gap layers and almost perfect light absorptance for both structures. The results showed that the enhancement of the electric field depends on the polarization of the incident light. For both polarizations, the periodic circular nanodisk array showed a stronger field enhancement with an electric field enhancement factor of 6.6 × 106 and TE polarization, and a larger absorptance of 98% at its dipole resonance wavelength, indicating the fundamental plasmonic mode. In addition, weaker resonant modes were observed in the absorptance and reflectance spectra of both nanostructures, with the nanostrips exhibiting sharper and stronger higher-order modes, making them suitable for applications requiring precise wavelength selectivity and narrow-band responses. Despite their different geometric shapes, both structures exhibited similar optimized metal film thickness and nanoparticle height, comparable modes in number and position, and identical optimized light incidence angles. Furthermore, increasing the dielectric gap layer thickness and optimizing it to a specific value revealed its ability to measure the refractive index, making it a promising candidate for sensing applications.

Unveiling the Nanoscale Dielectric Gap and Its Influence on Ferroelectric Polarization Switching in Scanning Probe Microscopy

AbstractThe dielectric gap between the scanning probe microscopy (SPM) tip and the surface of a ferroelectric using conductive atomic force microscopy and piezoresponse force microscopy (PFM) is investigated. While the gap functions as a dielectric layer, it also allows tunneling current to inject charges into the ferroelectric when a critical loading force between 10–20 µN is applied to a tip with a radius of 25 nm under a bias voltage of 0.5 V. It is observed that the permittivity of the dielectric gap determines the coercive voltage measured by the piezoresponse hysteresis loop. While such studies done in air often produce coercive voltages much larger than those studied for the same materials in capacitor‐based studies, the use of high permittivity media such as water (ɛr = 79) or silicone oil (ɛr = 2.1‐2.8) produces coercive fields that more closely match those measured in conventional capacitor‐based polarization hysteresis loop measurements. Furthermore, using water as a dielectric medium in PFM imaging enhances the accuracy in extracting the amplitude and phase data from periodically poled lithium niobate crystals. These findings provide insight into the nanoscale phenomena of polarization switching instigated by the SPM tip and provide a pathway to improved quantitative studies.

Pendant Group Functionalization of Cyclic Olefin for High Temperature and High-Density Energy Storage.

High-temperature flexible polymer dielectrics are critical for high-power-density energy storage and conversion under harsh operating conditions. These types of dielectrics will need to simultaneously possess a high bandgap, dielectric constant and glass transition temperature - a substantial challenge when designing novel dielectric polymers. In this work, by varying halogen substituents of an aromatic pendant hanging off a bicyclic mainchain polymer, a class of high-temperature olefins with adjustable thermal stability are obtained, all with uncompromised large bandgaps. Halogens substitution of the pendant groups at para or ortho position of polyoxanorborneneimides (PONB) imparts it with tunable high glass transition temperature from ∼220 to 245°C, while with also moderate dielectric constant of ∼ 2.8-3.0 and high breakdown strength of ∼625-800MV/m. A high energy density of 7.1 J/cc at 200°C is achieved with p-POClNB, representing the highest reported energy density among all-organic homo-polymer dielectrics. Molecular dynamic simulations and ultrafast infrared spectroscopy were used to probe the free volume element distribution and chain relaxations of the polymers to provide insights to the dielectric thermal properties. An increase in free volume element is observed with the change in the pendant group from fluorine to bromine at the para position; however, a decrease in free volume element is observed as we change the pendant group from fluorine to chlorine at the ortho position because of the steric hindrance. Overall, the dielectric constant and band gap remain stable while the glass transition temperature changes more obviously. Consequently, by proper designing the pendant groups, the thermal stability of PONB can be improved for harsh condition electrification. This article is protected by copyright. All rights reserved.

Transition metal ion doped Mg-Zn manganites for optoelectronic device applications

This work aimed at synthesizing Mg0.5Zn0.5Mn1.95(Fe/Co/Ni)0.05O4 nanoparticles using sol–gel auto-combustion method. Structural studies (XRD, Rietveld, Raman) confirmed the tetragonal spinel structure with I41/amd space group and average crystallite size ranged between 18–22.8 nm. The morphologies and compositions of these nanoparticles were studied using SEM and EDX. UV–Vis spectra demonstrated significant enhancement in the absorbance values. The estimated optical band gaps vary between 1.6 to 1.77 eV. Frequency-dependent dielectric and impedance spectroscopic studies (at room temperature) reveal exciting results. Thus, tailoring of dielectric properties and optical band gaps of these transition metals doped Mg-Zn manganite nanoparticles may find potential applications in optoelectronics devices.

Time-resolved characteristics of a nanosecond pulsed multi-hollow needle plate packed bed dielectric barrier discharge

In this paper, self-designed multi-hollow needle electrodes are used as a high-voltage electrode in a packed bed dielectric barrier discharge reactor to facilitate fast gas flow through the active discharge area and achieve large-volume stable discharge. The dynamic characteristics of the plasma, the generated active species, and the energy transfer mechanisms in both positive discharge (PD) and negative discharge (ND) are investigated by using fast-exposure intensified charge coupled device (ICCD) images and time-resolved optical emission spectra. The experimental results show that the discharge intensity, number of discharge channels, and discharge volume are obviously enhanced when the multi-needle electrode is replaced by a multi-hollow needle electrode. During a single voltage pulse period, PD mainly develops in a streamer mode, which results in a stronger discharge current, luminous intensity, and E/N compared with the diffuse mode observed in ND. In PD, as the gap between dielectric beads changes from 0 to 250 μm, the discharge between the dielectric bead gap changes from a partial discharge to a standing filamentary micro-discharge, which allows the plasma to leave the local area and is conducive to the propagation of surface streamers. In ND, the discharge only appears as a diffusion-like mode between the gap of dielectric beads, regardless of whether there is a discharge gap. Moreover, the generation of excited states and is mainly observed in PD, which is attributed to the higher E/N in PD than that in ND. However, the generation of the radical in ND is higher than in PD. It is not directly dominated by E/N, but mainly by the resonant energy transfer process between metastable and . Furthermore, both PD and ND demonstrate obvious energy relaxation processes of electron-to-vibration and vibration-to-vibration, and no vibration-to-rotation energy relaxation process is observed.

Synthesis Of Nano-Porous Strontium Titanate Materials for Photocatalysis

Strontium titanate semiconductor materials have been widely used in the field of photocatalysis due to their high dielectric constant and band gap. Uniform, micron-sized SrTiO3 particles didn’t tend to aggregate, and the low surface area of larger particles could be improved by incorporating porous structures, thus offering superior performance for a range of applications. In this study, six mainly methods to prepare nano-porous SrTiO3 particles were showed and discussed. The methods include hydrothermal method，sol gel method, chemical co-precipitation method, high temperature solid phase method, hard template method and soft template method. These processes and their advantages and disadvantages were analysised.

Impact of Alpha Rays on the Optoelectronic Properties of Epoxy Resin Thick Films

Irradiated epoxy thick films are important for optical properties and may be used in many optical applications. This study aims to evaluate the effect of alpha irradiation on the optical and structural properties of epoxy thick films. Epoxy resin films were prepared by mixing epoxy resin (A) with hardener (B) at a mixing ratio of 3:1. Thus, specific thick films with thicknesses of 0.7 mm,0.8 mm and 1 mm were manufactured. Using visible and ultraviolet spectroscopy is one of the most important methods for studying polymers band gaps and electrical properties. The absorbance and transmittance spectra were used to investigate the optical properties of epoxy coatings of different thicknesses over a wavelength range of 300 nm–900 nm. Optical properties, such as absorption coefficient, refractive index, extinction coefficient, real dielectric constant, imaginary dielectric and optical band gap, were measured. The results show that the epoxy thick films have good optical transparency in the low-wavelength region. The results showed that increasing the thickness of the resin films decreased the optical energy gap and refractive index while increasing the absorption and extinction coefficients. In comparison, the effect of irradiation on an epoxy film of thickness 1 mm leads to an increase in the transmittance spectrum and energy gap and a decrease in the optical constants. The Fourier-transform infrared (FTIR) spectrum of the films was examined and showed the types of chemical bonds of the epoxy films before and after irradiation.

Investigation of photosensitive and photodetector characteristics of n-TPA-IFA/p-Si heterojunction structure

n-TPA-IFA organic material was synthesized and deposited on p-Si by spin coating method to produce n-TPA-IFA/p-Si heterojunction diode. We determined that the dielectric constant and energy band gap of TPA-IFA organic material were 3.91 and 3.37 eV by DFT/B3LYP/6-311G(d,p) method using on Gaussian 09 W, respectively, and the carrier type of TPA-IFA organic semiconductor material was also n-type at room temperature from temperature-dependent hall effect measurements. Using forward and reverse bias I–V measurements in the dark and under various light intensities, we examined the key electrical characteristics of the n-TPA-IFA/p-Si heterojunction diode, including Φb\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\Phi }_{b}$$\\end{document} and n\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n$$\\end{document}. It was determined that the rectification ratio (RR) was approximately 104. The reverse current's observed increasing behavior with increasing light indicates that the produced heterojunction diode can be utilized as a photodiode, detector, or sensor. The values of n, Φb\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\Phi }_{b}$$\\end{document}, and Io were determined using I–V data in dark as 1.34, 0.91 eV, and 7.25 9 10–12 A, respectively. On the other hand, when the n-TPA-IFA/p-Si heterojunction diode is exposed to 100 mW/cm2 illumination, these parameters were obtained as 1.85, 0.80 eV, and 5.11 9 10–10 A, respectively. Photovoltaic parameters such as short circuit current (Isc) and open circuit voltage (Voc) were determined as 0.018 mV, 0.08 A and 0.050 mV, 0.29 A under 20 mW/cm2 light and 100 mW/cm2 light intensity, respectively. The photodetector properties of n-TPA-IFA/p-Si heterostructure were explored at different light intensities, and the photoresponsivity (R), photosensitivity (PS), specific detectivity (D∗\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${D}^{*}$$\\end{document}), and linear dynamic range (LDR) of the heterojunction changed with reverse voltage and light intensity. It was found that as light intensity increased, the linear dynamic range (LDR), a crucial characteristic for image sensors, increased as well (10.15 dB and 18.84 dB for 20 and 100 mW/cm2).

CAPACITANCE EVALUATION ON PARALLEL-PLATE CAPACITORS BY MEANS OF FINITE ELEMENT ANALYSIS

The electric field distribution produced by any disposition of insulating and conducting materials is a key aspect in electrical design, but exact values can only be obtained in simple geometries. In this work, using commercially available F.E.M. software we show the influence of the edge-effect on the electric field distribution of a two parallel-plane conducting plates system surrounded by an insulating medium taking into account the thickness of the conducting plates. We compare our results with previous published works. Finally, we obtain the relationship between capacitance and insulation characteristics, insulation gap, plate dimensions and plate thickness.

CAPACITANCE EVALUATION ON PERPENDICULAR PLATE CAPACITORS BY MEANS OF FINITE ELEMENT ANALYSIS

In this work we show the influence of the edge-effect on the electric field distribution, and hence on inner capacitance and outer capacitance of the inclined angle, of a inclined-plate capacitor system in a plane, surrounded by an insulating medium taking into account the thickness of the conducting plates for a complete set of dimensions and insulating characteristics. Where available we compare our results with previous published works. Finally, using statistical tools, we obtain the expression for computing the relationship between capacitance and insulation characteristics, insulation gap, plate dimensions and inclined angle.

Dielectric, electrical and optical properties of a Ni-substituted double perovskite ceramic

In this report, iron based double perovskite oxide Ca2Fe0.85Ni0.15NbO6 was successfully synthesized adopting the solid state reaction method. The structure and microstructure along with the purity, frequency and temperature dependent dielectric properties, energy storage and band gap modulation properties of the ceramic is also discussed. The ceramic shows a small band gap with a high remnant polarization which aligns it toward ferroelectric photovoltaic device applications. The temperature stable dielectric constant of the material up to a high temperature range is useful for MLCC applications. The energy storage density of the material is calculated from room temperature hysteresis loop. The frequency variation of ac conductivity refers Jonscher’s law. The temperature variation of frequency exponent term n indicates CBH (correlated barrier hopping), model of the conduction mechanism in the sample. The presence of room temperature M-H loop with negligible magnetization and coercive value indicates the soft ferromagnetic behavior of the ceramic.

Single-emitter super-resolved imaging of radiative decay rate enhancement in dielectric gap nanoantennas

High refractive index dielectric nanoantennas strongly modify the decay rate via the Purcell effect through the design of radiative channels. Due to their dielectric nature, the field is mainly confined inside the nanostructure and in the gap, which is hard to probe with scanning probe techniques. Here we use single-molecule fluorescence lifetime imaging microscopy (smFLIM) to map the decay rate enhancement in dielectric GaP nanoantenna dimers with a median localization precision of 14 nm. We measure, in the gap of the nanoantenna, decay rates that are almost 30 times larger than on a glass substrate. By comparing experimental results with numerical simulations we show that this large enhancement is essentially radiative, contrary to the case of plasmonic nanoantennas, and therefore has great potential for applications such as quantum optics and biosensing.

Анализ несчастных случаев в электросетевых компаниях

The problem of accidents occurring during the operation of electric power facilities has remained relevant for a long time. The analysis of accidents makes it possible to develop measures to improve industrial safety at agricultural facilities and electrical networks that supply electricity to agricultural facilities and enterprises. For this purpose, the authors considered accidents that occurred in power grid companies of the Russian Federation in 2014‑2022. To conduct the research, they used data from Rosseti PJSC on accidents in power grid companies obtained with the Synergy Center software package. The program included data on the investigation of accidents in Form No. 1 in accordance with the order of the Russian Ministry of Labor dated April 20, 2022, No.223. The software package included 191 accidents, in which 200 people were injured for the period between 2014 and 2022. The analysis revealed 58% of fatal outcomes. The most common damaging factor, which caused 65 accidents (34%), is a breakdown of the dielectric air gap due to violation of the permissible distance to live parts by operational personnel of electric grid companies. The cause of 53 accidents (28%) was the violation of labor safety rules when working with electrical installations. The maximum number of accidents occurred from 8 am to 4 pm during the periods March-May and July-August. Of the 191 injured employees, 114 were (57%) operational personnel (electricians), 108 of them (54%) having work experience from 3 to 10 years. Conclusions are drawn about the need to introduce signaling devices and reverse transformation blocking, improve the qualifications of personnel and train them using virtual reality technology on digital twins of power grid facilities. The proposed organizational and technical measures will reduce the number of accidents in power grid companies in the Russian Federation

Theoretical research on a broadband terahertz absorber for thermally controlled radiation emission based on the epsilon-near-zero mode.

In this paper, a tunable and ultra-broadband terahertz (THz) absorber is proposed. The absorber, which is built upon the conventional metal-dielectric-metal tri-layer configuration, incorporates a KCl thin film within the dielectric gap situated between the top resonator and the middle dielectric layer. The simulation indicates that the absorber effectively captures more than 90% of terahertz waves between 3.6 and 7.3 THz, achieving absorption of over 99% within the 5.8-6.9 THz range. This unique broadband absorber is enabled by the interaction of plasmon and epsilon-near-zero (ENZ) modes. Additionally, due to the utilization of VO2 in the top resonator, the designed absorber holds potential to function as a thermally controlled radiation emitter, exhibiting a high emissivity of 90.5% at high temperatures while maintaining a low emissivity of 8.2% at low temperatures. The absorber is uncomplicated and adjustable, offering great potential for use in thermal management, terahertz camouflage, and engineering insulation.

Sculptured silicon nanopillars bridging face to face nanogaps with metal-insulator-metal coating for surface enhanced Raman spectroscopy

A multilayer structure of metal-insulator-metal (MIM) thin film on a sculptured silicon nanopillar (Si NP) is designed and optimized for surface-enhanced Raman spectroscopy (SERS) applications. A facile fabrication method of large-area periodic nanopillars was developed by combining reactive ion etching and monolayer polystyrene (PS) beads on a Si wafer to fabricate a regular array of Si NPs. The MIM-coated Si NP showed better Raman signal enhancement than a single metal layer-coated Si NP due to multidimensional coupled plasmonic enhancement at metal-dielectric interface. Further, the MIM-coated Si NPs showed better SERS activity than the MIM-coated unprocessed PS beads due to increased surface area for hotspot generation and coupling of plasmonic modes induced by the formation of closely located branches in sculpture pillar morphology. The shape- and size-dependent SERS activity of fabricated NPs and the dielectric gap layer variation for tuning plasmonic properties were investigated using rhodamine 6 G as a probe molecule. The investigation of plasmonic enhancement using finite difference time domain (FDTD) simulation provided insight into the distribution of hotspots and the amount of local electric field enhancement. Furthermore, the developed pillar exhibited distinct and enhanced peak of R6G up to 10−15 M concentrations.

Grid composite meta-surface absorber with thermal isolation structure for terahertz detection.

This paper specifically focuses on the absorber, the critical component responsible for the detector's response performance. The meta-surface absorber combines two resonant structures and achieves over 80% absorptance around 210 GHz, resulting in a broad operating frequency range. FR-4 is selected as the dielectric layer to be compatible with standard printed circuit board (PCB) technology, which reduces the overall fabrication time and cost. The absorbing unit and array layout are symmetrically designed, providing stable absorptance performance even under incident waves of different polarization angles. The polarization-insensitive absorptance characteristic further enhances the compatibility between the absorber and the detector in the application scenario. Furthermore, the thermal insulation performance of the absorber is ensured by introducing thermal insulation gaps. After completing fabrication through PCB technology, testing revealed that the absorber maintained excellent absorptance performance within its primary operating frequency range. This performance consistency closely matched the simulation results.

Simulation and experimentation of renewable dielectric gap flow fields in EDM

Simulation and experimentation of renewable dielectric gap flow fields in EDM

Trend Synthesis Thin Film Research as Electronic Device (A Review)

A thin film is a material with optical properties highly dependent on the dielectric constant, refractive index, and gap energy. This research aims to identify and analyze research trends in thin-layer synthesis as electronic devices. This research is qualitative. The data used in this research was obtained from documents indexed by Google Scholar from 2014-2023 using Publish or Perish and Dimension.ai. Research procedures use PRISMA guidelines. The data identified and analyzed included the type of publication, author on thin layer synthesis, source of publication, and the title of research on thin layer synthesis that was widely cited. The data analysis method uses bibliometric analysis assisted by VOSviewer software. The results of the study show that the research trend in thin-layer synthesis has experienced a fluctuating increase from 2014 to 2020. The journal containing the most thin-layer synthesis articles is ECS Meeting Abstracts with 676. The results of the density mapping analysis show that the theme that is rarely researched is organic semiconductors, organic thin film transistors, and green synthesis.

Bionic Blade Lift‐Drag Combination Triboelectric‐Electromagnetic Hybrid Generator with Enhanced Aerodynamic Performance for Wind Energy Harvesting

AbstractThe triboelectric nanogenerator (TENG) is a promising technology with unique advantages for harvesting environmental high‐entropy energy like wind power. However, inefficient wind energy harvest devices have limited the operating wind speed and practical application of TENGs. In this work, a bionic blade lift‐drag hybrid turbine‐driven triboelectric‐electromagnetic hybrid generator (HT‐TEHG) is designed for broadband wind energy harvesting. The lift‐drag hybrid turbine combines the benefits of drag‐type blades enabling low wind speed start‐up and bionic lift‐type blades generating high torque, achieving an 11% increase in performance. The TENGs are designed with appropriate dielectric layer gaps to balance the output performance and friction torque and are independently driven by two types of blades to achieve self‐adaptive graded power generation at different wind speeds. The starting wind speed of the HT‐TEHG is 2 m s−1 and achieves a peak power of 202.4 mW with an energy conversion efficiency of 9.1% at a wind speed of 4 m s−1. The durability of the TENG is verified by continuous operation for 1 × 105 cycles with almost no performance degradation. Moreover, the HT‐TEHG can power a wireless weather station using natural wind. The study introduces a valuable approach to harvest broadband wind energy and enable distributed power for Internet of Things devices.