Leakage Current Behavior Research Articles

Correction: Structural, Dielectric, Electrical, Leakage Current Behavior of Calcined Compound; (Bi1/2Cs1/2)(Fe1/3Mn1/3W1/3)O3 for Electronic Devices

Correction: Structural, Dielectric, Electrical, Leakage Current Behavior of Calcined Compound; (Bi1/2Cs1/2)(Fe1/3Mn1/3W1/3)O3 for Electronic Devices

Risk assessment of contaminated composite insulators in pre-flashover conditions

In this paper, a novel approach for risk assessment of the outdoor polluted insulators is presented to predict dry band-arcing and flashover. Risk evaluation of the dry-band arcing and flashover are represented using leakage current (LC) behavior in order to understand pollution behavior of the pre-flashover conditions. Critical indexes of the dry-band arcing and flashover are extracted based on the presented risk assessment model using wavelet transform (WT). Then, the developed critical indexes are used for prediction of the operation risk of the composite insulators. In addition, the occurrence probabilities of the dry band arcing and flashover are calculated based on the analysis of critical indexes. Several sensitivity parameters including pollution level, wetting rate and geometry specification are considered in the presented model. Validation results show that risk of the insulator's service can be correlated to the represented critical indexes. The proposed approach can be adopted as an online monitoring tool in order to avoid pollution flashover of the outdoor insulators.

Probing the potential of CdZnTe for high-energy high-flux 2D X-ray detection using the XIDer incremental digital integrating readout

The latest synchrotron radiation sources have the capability to produce X-ray beams with a photon flux that can be up to three orders of magnitude higher than previous-generation facilities, and that are not manageable by the currently available 2D photon-counting pixel detectors. The construction of new detectors that exceed the limitations of existing devices is a critical strategic need. Developing such detectors is a challenge in terms of readout electronics as well as sensor material, particularly in the case of devices intended to operate at X-ray energies above 30 keV. The approach adopted at the ESRF to deal with this major difficulty is twofold: the use of a novel semiconductor material with improved electrical properties, high-flux CdZnTe, and the investigation of a specific readout scheme, incremental digital integration, via the XIDer project in collaboration with the University of Heidelberg. Incremental digital integration is a method intended to be less sensitive to variations of the dark current than the conventional charge integration readout. However, this readout scheme requires that the leakage current from the sensor material stays below a certain threshold to reduce the leakage contributions. This paper introduces the ESRF strategy and few examples of the methods employed to evaluate the performance and leakage current behavior of high-flux CdZnTe pixelated sensors. These examples illustrate the first results obtained with this material under moderate to very high X-ray irradiation fluxes of up to 1012 photons/mm2/s.

Structural, Dielectric, Electrical, Leakage Current Behavior of Calcined Compound; (Bi1/2Cs1/2)(Fe1/3Mn1/3W1/3)O3 for Electronic Devices

Structural, Dielectric, Electrical, Leakage Current Behavior of Calcined Compound; (Bi1/2Cs1/2)(Fe1/3Mn1/3W1/3)O3 for Electronic Devices

Effect of zinc and magnesium ion doping on leakage current behavior of Ba0.6Sr0.4TiO3 thin film.

We report an in-depth analysis of the carrier conduction mechanisms in multilayer doped Ba0.6Sr0.4TiO3 films, which offers a significant new message for reducing the leakage current. First, Ba0.6Sr0.4TiO3 (BST) sol, Ba0.6Sr0.4Ti0.99Zn0.01O3 (ZBST) sol, and Ba0.6Sr0.4Ti0.99Mg0.01O3 (MBST) sol were prepared using the sol-gel method. Then, BST, ZBST, MBST, and binary alternating-structure Ba0.6Sr0.4Ti0.99Zn0.01O3/Ba0.6Sr0.4Ti0.99Mg0.01O3/Ba0.6Sr0.4Ti0.99Zn0.01O3 (ZMZ) thin films were designed and prepared. The effects of single-component doping and binary alternating doping on the interface barrier height and trap barrier height of the Ba0.6Sr0.4TiO3 thin films were studied. The results showed that the interface barrier height of ZMZ thin films is 0.55 eV, and the interface barrier height of BST thin films is 0.53 eV. Compared with the ZBST and MBST thin films, the change in the interface barrier height of the ZMZ film was not obvious. The trap barrier height of the ZMZ thin film is 0.17 eV, and the trap potential barrier height of the BST thin film is 0.12 eV. The trap barrier heights of ZBST thin films and MBST thin films are 0.15 eV and 0.16 eV, respectively. The enhancement of the trap barrier height may be related to the weakening of the trap and donor effects caused by oxygen vacancy defects. The energy band diagram shows the relationship between the oxygen vacancy defects, interface barrier height, and trap barrier height.

Synthesis and characterization of (1-x)Bi0.9Sm0.1FeO3 - (x)BaZr0.15Ti0.85O3 based solid solution: Temperature-dependent dielectric and impedance properties

Lead-free solid solution of (1-x) Bi0.9Sm0.1FeO3 − (x) BaZr0.15Ti0.85O3 (BSFO − BZT) (x = 0.0, 0.10, 0.15, 0.20, 0.25, 0.50) ceramics were prepared using solid-state reaction method. The structural, morphological, temperature-dependent dielectric properties and leakage current were investigated. The structural investigation revealed the formation of perovskite structure coexisting with tetragonal and rhombohedral phases within (BSFO–BZT) ceramics. The dielectric measurements (within 303 K-773 K) confirmed the existence of a morphotropic phase boundary at x = 0.15 for the (BSFO–BZT) system. The frequency and temperature dependent electrical behavior were explained using Ac conductivity and impedance analysis. The leakage current behavior for all these samples was investigated using both space charge-limited conduction (SCLC) for bulk and Schottky emission (SE) for limited interface conduction approach, whereas the pure BSFO sample was found to be dominated by ohmic conduction, while the BZT-doped samples were dominated by grain boundary-limited conduction.The sample (0.80)Bi0.9Sm0.1FeO3-(0.15)BaZr0.15Ti0.85O3 achieved largest dielectric constant 330 at 10 KHz along with a moderate leakage current density value of 3.54 × 10-5A/cm2 (which is quite lower than pure BSFO) proven its candidacy to develop a stable photovoltaic, multilayer actuators, and ferroelectric memory devices.

Investigating the degradation mechanisms of moisture on the reliability of integrated low-k stack

This study investigates the phenomenon of moisture diffusion within integrated circuits, focusing on low-k and SiCN dielectric materials. The research confirms the main pathway of moisture diffusion occurring through interfaces between materials. The various steps involved in the moisture diffusion mechanism are identified and linked to electrical characterizations, including variations in capacitance, modifications in leakage current behavior, and dielectric breakdown. A modification in the conduction mechanism is observed. The investigation also highlights different types of bonds formed between the dielectrics and moisture based on literature review and baking process. Saturated samples exhibit a partial reversibility after a 250 °C bake but do not fully recover. Nevertheless, reversibility is shown to be dependent on the moisture content reached prior to baking.

Investigation of the time dependent gate dielectric stability in SiC MOSFETs with planar and trench gate structures

In this work, the time-dependent dielectric breakdown (TDDB) analysis is performed to understand the gate oxide reliability in SiC MOSFETs with two different structures, i.e., planar and trench gate structures. We have discovered different gate leakage current behaviors between the SiC MOSFETs with planar gate (Sample A) and trench gate (Sample B) during the forward gate bias stress. Notably, the slight increase of the gate current during the stress and the negative activation energy (Ea = −0.07 eV) observed in Sample A suggest that the hole generation caused by the impact ionization can be occurred during the forward gate TDDB tests. Furthermore, the SiC MOSFETs with trench gate structure (Sample B) exhibit the operation voltage of 55.7 V (exponential law) and 57.3 V (power law) for the 0.001 % failure of 30 years under 175 °C, indicating that SiC trench gate MOSFETs with enough thick gate dielectric (87.1 nm (bottom) and 77.9 nm (sidewall)) can have the promising forward gate TDDB stability.

Understanding the Charge Carrier Dynamics, Improved Dielectric Properties and Leakage Current Behaviour of NiFe1.85Dy0.15O4 with Structural Correlation

This research explores the charge carrier dynamics of NiFe1.85Dy0.15O4 with excess amounts of Dy ions replacing the metal ions and forming an additional orthorhombic phase of DyFeO3 confirmed by the X-ray diffraction pattern of the sample and validated by Scanning electron microscopy and UV-Visible studies. Dy incorporation, in conjunction with the additional phase, has been shown to alter the structure of the inverse spinel matrix by expanding the unit cell and inducing strain. Impedance spectroscopy was used to investigate the sample’s behaviour as a circuit element, and an equivalent circuit containing resistance, capacitance, and inductance was realized to represent the sample when exposed to an alternating field. The Cole-Cole model of non-Debye relaxation was used to calculate dielectric parameters such as dielectric strength, high-frequency permittivity, shape parameters, and dielectric relaxation times. The specimen’s leakage current conduction mechanism was also systematically investigated to determine the presence of different variants of bulk and interface-limited conduction processes. This multifaceted study not only reveals the intriguing charge dynamics of NiFe1.85Dy0.15O4, which are influenced by Dy-ion incorporation and the emergence of a new phase but also extends its implications to the realm of potential applications, spurring developments in areas like novel energy storage technologies and advanced electronics.

Great enhancement of ferroelectric properties of Al2O3-modified BiFeO3 thin films obtained by sol-gel method

Thin films prepared by sol-gel method usually have a large leakage current, which hinders their practical applications. Therefore, it is extremely important to adopt effective strategies to reduce their leakage current. In this work, BiFeO3 thin films with Al2O3 modification, either in the format of layer insertion or evenly-distributed particles incorporation, are fabricated by a sol-gel method on the Pt(111)/Ti/SiO2/Si substrates. It was found that an optimal amount of Al2O3 in the system can greatly compress the leakage current and enhance the ferroelectric properties. For BiFeO3 films with thickness in the ∼300 nm range, remnant polarization (Pr) of ∼ 40.82, 80.08, 61,6 μC/cm2, and maximum polarization (Pmax) of ∼ 62, 157, 90 μC/cm2 can be achieved for Al2O3 modification via 1/3, 1/5 layer insertion and 1:5 particle incorporation, respectively. Additionally, we systematically investigated the impact of Al2O3 on the phase microstructure, leakage current, and conduction mechanism behavior of Al2O3-modified BiFeO3 films. The results not only promote the sol-gel method as a promising method for preparing high-quality ferroelectric thin films with compressed leakage, but also promote the potential applications of BiFeO3 thin films in electromechanical devices.

Magnetoelectric multiferroic properties of BaTiO3-CoFe2O4-BaTiO3 tri-layer thin films fabricated by pulsed laser deposition

A magnetoelectric multiferroic bi-phase system with robust ferroelectric and ferro/ferri-magnetism response at room temperature would be ideally suitable for microelectronics, memory devices, and for spintronic applications. BaTiO3/CoFe2O4/BaTiO3(BTO/CFO/BTO) heterostructured films were pulsed laser deposition grown on Pt(111)/TiO2/SiO2/Si substrates. High quality polycrystalline films were grown by thermal annealing at 750 °C, at an oxygen partial pressure of 100 mTorr for 1 h. Crystal quality and phase formation information was monitored using X-ray diffraction (XRD). XRD confirm the growth of polycrystalline heterostructures and the coexistence of both perovskite BTO and spinel CFO phases in heterostructures. In order to obtain robust magnetoelectric coupling, we studied the tri-layer structure as a representative ferroelectric/ferrimagnetic/ferroelectric system. We report the ferroelectric, leakage current behavior, ferrimagnetic, and frequency dependent ME properties of the films. Ferroelectric BTO and ferrimagnetic inverse spinel CFO nature is also confirmed using the piezoresponse force microscopy and magnetic force microscopy measurements. These nanostructures exhibit high saturation polarization (Ps ∼ 99.86 µC/cm2), saturation magnetization (Ms ∼ 51.48 emu/cm3), and a strong ME coupling coefficient of ∼ 274 mV/cm-Oe with a bias magnetic field of + 90 Oe, anda frequency of 1 kHz revealing them as prospective candidates for multifunctional applications.

Effect of internal interface layer on dielectric properties of doped Ba0.6Sr0.4TiO3 thin films and its simulation in filters

Effect of the internal interface layer on the dielectric properties of doped Ba0.6Sr0.4TiO3 (BST) films and their simulation research in filters. Based on the interfacial effect in the multi-layer ferroelectric thin film, a different number of internal interface layers was proposed and introduced into the Ba0.6Sr0.4TiO3 thin film. First, Ba0.6Sr0.4Ti0.99Zn0.01O3 (ZBST) sol and Ba0.6Sr0.4Ti0.99Mg0.01O3 (MBST) sols were prepared using the sol-gel method. Ba0.6Sr0.4Ti0.99Zn0.01O3/Ba0.6Sr0.4Ti0.99Mg0.01O3/Ba0.6Sr0.4Ti0.99Zn0.01O3 thin films with 2 layer internal interface layer, 4 layer internal interface layer and 8 layer internal interface layer were designed and prepared (I2, I4, I8). The effects of the internal interface layer on the structure, morphology, dielectric properties, and leakage current behavior of the films were studied. The results showed that all the films were of the cubic perovskite BST phase and had the strongest diffraction peak in the (110) crystal plane. The surface composition of the film was uniform, and there was no cracked layer. When the bias of the applied DC field was 600 kV cm−1, the high-quality factor values of the I8 thin film at 10 MHz and 100 kHz were 111.3 and 108.6, respectively. The introduction of the internal interface layer changed the leakage current of the Ba0.6Sr0.4TiO3 thin film, and the I8 thin film exhibited the minimum leakage current density. The I8 thin-film capacitor was used as the tunable element to design a fourth-step ‘tapped’ complementary bandpass filter. When the permittivity was reduced from 500 to 191, the central frequency-tunable rate of the filter was 5.7%.

High-energy-density flexible graphene-based supercapacitors enabled by atypical hydroquinone dimethyl ether

Supercapacitor is an electrochemical energy-storage technology that can meet the green and sustainable energy needs of the future. However, a low energy density was a bottleneck that limited its practical application. To overcome this, we developed a heterojunction system composed of two-dimensional (2D) graphene and hydroquinone dimethyl ether- an atypical redox-active aromatic ether. This heterojunction displayed a large specific capacitance (Cs) of 523 F g−1 at 1.0 A g−1, as well as good rate capability and cycling stability. When assembled in symmetric and asymmetric two-electrode configuration, respectively, supercapacitors can work in voltage windows of 0 ∼ 1.0 V and 0 ∼ 1.6 V, accordingly, and exhibited attractive capacitive characteristics. The best device can deliver an energy density of 32.4 Wh Kg−1 and a power density of 8000 W Kg−1, and suffered a small capacitance degradation. Additionally, the device showed low self-discharge and leakage current behaviors during long time. This strategy may inspire exploration of aromatic ether electrochemistry and pave a way to develop electrical double-layer capacitance (EDLC)/pseudocapacitance heterojunctions to boost the critical energy density.

A New Nine-Level Highly Efficient Boost Inverter for Transformerless Grid-Connected PV Application

Transformerless grid-connected multi-level <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PV</i> (photovoltaic) inverter has the major concern of leakage current and buck behavior of output voltage, hence not suitable for low voltage PV applications. A new <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">9L4x</i> (nine-level quad boost) highly efficient inverter based on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</i> (switched capacitor) with a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CG</i> (common ground) configuration has been proposed in this paper, which provides four times the gain of input voltage. Hence, this inverter is preferable for low voltage <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PV</i> applications without any boost dc/dc converter intermediate stage. The inverter is designed in such a way that total conducting switches for different level generation is minimum. This technique helps to increase the efficiency of the inverter. Two <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SC</i> cells are utilized to step-up the input <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PV</i> voltage and facilitate nine steps in output voltage. The common grounding feature of the proposed inverter topology helps mitigate the leakage current. Additionally, this new inverter can handle reactive power during the grid’s lagging/leading pf (power factor) condition. To regulate the active and reactive grid power, a <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> (proportional resonant) controller is designed. The proposed modulation strategy balances the voltages of switched capacitors at their base voltage with allowable ripple. The inverter circuit details, control strategy, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PWM</i> (pulse width modulation) scheme, thermal modeling, and loss analysis with component design guidelines are described in detail. Experimental results are presented to validate the effectiveness and feasibility of this proposed inverter.

Influence of Fibroin Membrane Composition and Curing Parameters on the Performance of a Biodegradable Enzymatic Biosensor Manufactured from Silicon‐Free Carbon

Herein, fibroin, polylactide (PLA), and carbon are investigated for their suitability as biocompatible and biodegradable materials for amperometric biosensors. For this purpose, screen‐printed carbon electrodes on the biodegradable substrates fibroin and PLA are modified with a glucose oxidase membrane and then encapsulated with the biocompatible material Ecoflex. The influence of different curing parameters of the carbon electrodes on the resulting biosensor characteristics is studied. The morphology of the electrodes is investigated by scanning electron microscopy, and the biosensor performance is examined by amperometric measurements of glucose (0.5–10 mM) in phosphate buffer solution, pH 7.4, at an applied potential of 1.2 V versus a Ag/AgCl reference electrode. Instead of Ecoflex, fibroin, PLA, and wound adhesive are tested as alternative encapsulation compounds: a series of swelling tests with different fibroin compositions, PLA, and Ecoflex has been performed before characterizing the most promising candidates by chronoamperometry. Therefore, the carbon electrodes are completely covered with the particular encapsulation material. Chronoamperometric measurements with H2O2 concentrations between 0.5 and 10 mM enable studying the leakage current behavior.

The Influence of Extended Defects in 4H-SiC Epitaxial Layers on Gate Oxide Performance and Reliability

For the ongoing commercialization of power devices based on 4H-SiC, increasing the yield and improving the reliability of these devices is becoming more and more important. In this investigation, gate oxide on 4H-SiC was examined by time-zero dielectric breakdown (TZDB) and constant current stress (CCS) time-dependent dielectric breakdown (TDDB) method in order to get insights into the influence of the epitaxial defects on the gate oxide performance and reliability. For that purpose, MOS capacitors with different gate oxides have been fabricated. Crystal defects in the epitaxial layers have been detected and mapped by ultraviolet photoluminescence (UVPL) and interference contrast (DIC) imaging. The results of the comparison of electrical data and surface mapping data indicate a negative influence on the leakage current behavior for some extended epitaxial defects. Results from TDDB measurement indicated numerous extrinsic defects, which can be traced back to gate oxide processing conditions and defect densities.

TCAD Analysis of Leakage Current and Breakdown Voltage in Small Pitch 3D Pixel Sensors.

Small-pitch 3D pixel sensors have been developed to equip the innermost layers of the ATLAS and CMS tracker upgrades at the High Luminosity LHC. They feature 50 × 50 and 25 × 100 μm2 geometries and are fabricated on p-type Si-Si Direct Wafer Bonded substrates of 150 μm active thickness with a single-sided process. Due to the short inter-electrode distance, charge trapping effects are strongly mitigated, making these sensors extremely radiation hard. Results from beam test measurements of 3D pixel modules irradiated at large fluences (1016neq/cm2) indeed demonstrated high efficiency at maximum bias voltages of the order of 150 V. However, the downscaled sensor structure also lends itself to high electric fields as the bias voltage is increased, meaning that premature electrical breakdown due to impact ionization is a concern. In this study, TCAD simulations incorporating advanced surface and bulk damage models are used to investigate the leakage current and breakdown behavior of these sensors. Simulations are compared with measured characteristics of 3D diodes irradiated with neutrons at fluences up to 1.5 × 1016neq/cm2. The dependence of the breakdown voltage on geometrical parameters (e.g., the n+ column radius and the gap between the n+ column tip and the highly doped p++ handle wafer) is also discussed for optimization purposes.

Structural, electrical and leakage current behaviour of double perovskite Gd2NiTiO6

This work discusses the synthesis, characterization, and electrical properties of Gd2NiTiO6 (GNTO) double perovskite synthesized using the sol-gel citrate auto-ignition method. The structure, microstructure, and compositional distribution of the sample were analyzed by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), and Energy Dispersive X-ray (EDX) analysis. Rietveld's refinement of the XRD pattern corroborated the single-phase monoclinic structure with space group P21/n. The impedance spectra demonstrated grain and grain boundary contributions to the total conductivity and the non-Debye type relaxation. The electrical study also established the semiconductive character of the material. The investigation showed that the conduction mechanism was thermally activated. The frequency-dependent complex dielectric spectra have been investigated using the Havriliak-Nigami (HN) formalism. The temperature variation of leakage-current density was found from J-E characteristics curves.

Leakage Current Behavior in HfO2/SiO2/Al2O3 Stacked Dielectric on 4H-SiC Substrate

Leakage Current Behavior in HfO₂/SiO₂/Al₂O₃ Stacked Dielectric on 4H-SiC Substrate

Structure and leakage current behavior of GaFe0.95Mg0.05O3 ceramic

GaFe0.95Mg0.05O3 ceramic sample was synthesized through sol–gel technique. The effect of Magnesium (Mg) doping on the structural and leakage current density of gallium ferrite (GaFeO3) was studied in detail. The structural properties of prepared sample were investigated by X-ray diffraction (XRD) and Raman spectroscopy. The single orthorhombic phase was observed without existence of any impurity phases. Moreover, the same number of Raman modes were observed in the Raman spectra which further confirms the single phase of GaFeO3. The lattice parameters were calculated using Rietveld refinement and revealed the increment in lattice parameters with doping of Mg in GaFeO3. The significant reduction is observed in leakage current density (approximately-four orders of magnitude) with the incorporation of Mg.