Application Of Positive Voltage Research Articles

Alumina Graphene Catalytic Condenser for Programmable Solid Acids

Precise control of electron density at catalyst active sites enables regulation of surface chemistry for the optimal rate and selectivity to products. Here, an ultrathin catalytic film of amorphous alumina (4 nm) was integrated into a catalytic condenser device that enabled tunable electron depletion from the alumina active layer and correspondingly stronger Lewis acidity. The catalytic condenser had the following structure: amorphous alumina/graphene/HfO2 dielectric (70 nm)/p-type Si. Application of positive voltages up to +3 V between graphene and the p-type Si resulted in electrons flowing out of the alumina; positive charge accumulated in the catalyst. Temperature-programmed surface reaction of thermocatalytic isopropanol (IPA) dehydration to propene on the charged alumina surface revealed a shift in the propene formation peak temperature of up to ΔT peak∼50 °C relative to the uncharged film, consistent with a 16 kJ mol-1 (0.17 eV) reduction in the apparent activation energy. Electrical characterization of the thin amorphous alumina film by ultraviolet photoelectron spectroscopy and scanning tunneling microscopy indicates that the film is a defective semiconductor with an appreciable density of in-gap electronic states. Density functional theory calculations of IPA binding on the pentacoordinate aluminum active sites indicate significant binding energy changes (ΔBE) up to 60 kJ mol-1 (0.62 eV) for 0.125 e- depletion per active site, supporting the experimental findings. Overall, the results indicate that continuous and fast electronic control of thermocatalysis can be achieved with the catalytic condenser device.

Can Anions Be Inserted into MXene?

Despite the continuous progress in the research and development of Ti3C2Tx (MXene) electrodes for high-power batteries and supercapacitor applications, the role of the anions in the electrochemical energy storage and their ability to intercalate between the MXene sheets upon application of positive voltage have not been clarified. A decade after the discovery of MXenes, the information about the possibility of anion insertion into the restacked MXene electrode is still being questioned. Since the positive potential stability range in diluted aqueous electrolytes is severely limited by anodic oxidation of the Ti, the possibility of anion insertion was evaluated in concentrated aqueous electrolyte solutions and aprotic electrolytes as well. To address this issue, we have conducted in situ gravimetric electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) measurements in highly concentrated LiCl and LiBr electrolytes, which enable a significant extension of the operation range of the MXene electrodes toward positive potentials. Also, halogens are among the smallest anions and should be easier to intercalate between MXene layers, in comparison to multiatomic anions. On the basis of mass change variations in the positive voltage range and complementary density functional theory calculations, it was demonstrated that insertion of anionic species into MXene, within the range of potentials of interest for capacitive energy storage, is not likely to occur. This can be explained by the strong negative charge on Ti3C2Tx sheets terminated by functional groups.

Doubly forced anharmonic oscillator model for floating potential fluctuations in DC glow discharge plasma

The Floating Potential Fluctuations (FPF) observed in a dc glow discharge plasma powered with two sources is modeled using an anharmonic oscillator with two forcing terms. In the discharge system, one of the electrode is biased to a negative voltage source (i.e. cathode), and the second electrode is biased to a positive voltage source (i.e. anode), while the stainless-steel vacuum chamber is grounded. The dc glow discharge plasma is generated by application of negative voltage on the cathode with respect to the grounded chamber using one of the power supplies. On application of positive voltage to the anode using second power supply results in formation of potential structure on achieving the triggering criteria. This potential structure is referred as anodic double layer (ADL). The evolution of ADL is associated with FPF. Therefore, FPF is analyzed to characterize the ADL's dynamical features. In this work, the experimentally observed FPF compared with numerically obtained oscillations using an anharmonic oscillator model with two forcing terms. Each of these forcing terms are associated with the two power supplies used in the experiment. The experimentally and numerically obtained oscillations from the model are studied using phase-space plot, FFT, Largest Lyapunov exponent (LLE). The dynamical features of oscillations obtained by the model show strong agreement with the experiment and can be extended for a description of complex systems driven by multiple forces.

Polarity effect of breakdown characteristics across micrometer‐scale surface gap

AbstractWith a miniaturization of electrical devices, the gap between electrode becomes lower and lower. In order to optimize the insulation design, the understanding of breakdown phenomenon across micrometer‐scale gap is essential. In this study, breakdown characteristics across micrometer‐scale gap was investigated based on experiment and numerical simulation. The result shows that the breakdown voltage under positive voltage application is 1.5 times higher than the one under the negative voltage application. The polarity effect can be explained by the source of initial electrons. Under negative voltage application, the initial electrons are emitted from the cathode surface based on Fowler‐Nordheim equation. On the other hand, under positive voltage application, the insulator plays an important role on breakdown voltage.

Effect of Specific Surface Area of Counter Electrode in Hybrid Capacitor Type Electrochromic Device

We have already reported a novel hybrid capacitor multicolor electrochromism (EC) in a single device by introducing a porous capacitive counter electrode, ITO particle-modified electrode.1 Due to the formation of the electrical double layer on the counter electrode successfully compensated the charge consumption of EC reaction enables certain colors to be represented selectively both anodic and cathodic EC molecules by just using two electrodes and sandwiched electrolyte. In our another paper, we also found that the capacitance has a greater impact on the appearance of multiple colors.2 Beyond those, in practical EC applications, the performance of coloration, response time also play very important roles. In this regard, the effect of the increase of specific surface area of counter electrode on the EC properties of the hybrid capacitor ECD has not been studied in detail. In this paper, we fabricated several ECDs having hybrid capacitor structure with flat ITO electrode as the working side and ITO particle-modified electrodes which having different thickness (aim to increase the specific surface area) as the counter side. As the EC molecule, we employed the molecule of 10-methylphenothiazine (MPT). We discussed the effect of increased specific surface area of the counter electrode on the EC properties in the hybrid capacitor ECD. We measured the capacitance of the ITO particle-modified electrodes having different thickness. Fig. 1 shows the relationship between electrostatic capacitance and thickness of ITO particle-modified electrodes. From the result, we can clearly know that with the increase of thickness, the capacitance showed an increasing trend. Fig. 2 shows the transmission spectra of the ECDs under application of positive voltage of 1.2 V for 10 s. The transmittance of ECDs decreased strongly due to oxidized MPT molecule appeared at around 515 nm. As the result, color of ECDs changed from transparent state to pink color. At the same driving condition, with the increase of thickness, the amount of charge consumed by EC reaction increased, leading to more obvious ΔT. This result can be explained that with the larger capacitance due to increased specific surface area leading to larger accumulation of electrical charge on the counter electrode, oxidative reaction of the MPT was promoted on the working electrode, toward increased density of pink color.

Frequency-switchable polarity-inverted BAW resonators based on electric-field-induced piezoelectric PMN-PT/PZT epitaxial film stacks

Spontaneous polarization of tetragonal ferroelectrics cannot be inverted unless the applied electric field is greater than the coercive field. In the case of the cubic phase, on the other hand, polarization and piezoelectricity can be induced merely by applying an electric field. In this study, we proposed polarity-inverted cubic/tetragonal multilayer film resonators which allow switching between the fundamental and high-order mode resonances through the independent control of the polarization of the cubic layer. Frequency switching in bulk acoustic wave (BAW) resonators based on all-epitaxial cubic 0.95Pb(Mg1/3Nb2/3)O3 (PMN)-0.05PbTiO3 (PTO)/tetragonal Pb(Zr,Ti)O3 (PZT) bilayer film stacks is demonstrated theoretically and experimentally. Under a negative voltage application, which is less than the coercive field of the tetragonal PZT layers, a fundamental mode resonance (327 MHz) is observed, whereas a second-mode resonance (779 MHz) is observed under a positive voltage application in BAW resonators. A theoretical simulation based on Mason’s equivalent circuit model, taking account of the polarity-inverted bilayer structure, shows good agreement with the experimental results.

Similarity of potential-induced degradation in superstrate-type thin-film CdTe and Si photovoltaic modules

Degradation phenomena under high-voltage stress, referred to as potential-induced degradation (PID) in general, were studied in superstrate-type thin-film photovoltaic (PV) modules, such as CdTe and thin-film Si PV modules. Both deterioration in the PV performance and delamination of the transparent conducting oxide (TCO) layer on the glass substrate were observed by the PID test for both PV modules, although a change in the PV parameters during the PID test with negative voltage application was somewhat different between them. It was also found for both PV modules that recovery from PID is accomplished by positive voltage application and that quick and drastic deterioration in all the PV parameters occurs by the second negative voltage application after recovery. It is suggested that the common origin of PID for superstrate-type thin-film PV modules is damage and delamination of the TCO layer.

Novel electrophoretic acetonitrile-based stacking for sensitive monitoring of the antiepileptic drug perampanel in human serum

Perampanel is a novel antiepileptic drug used in paediatric patients. Existing methods that determine serum perampanel are of limited practicability. We developed a novel capillary electrophoresis (CE) method using a new version of acetonitrile stacking for on-line sample pre-concentration, and fluorescence detection (FD). CE separations were performed in a fused-silica capillary where the electroosmotic flow was reduced by coating the inner surface using a INST coating solution. The optimised background electrolyte composition was 50 mM chloroacetic acid with addition of 0.5% m/v polyvinylalcohol (pH 2.15) and separation was driven by application of positive voltage + 30 kV. Serum samples (25 μL) treated by the addition of acetonitrile in a ratio of 1:3 v/v were each injected into the capillary at a large volume that corresponded to the length (129 mm) of the sample zone (hydrodynamic pressure impulse 6000 mbars). Acetonitrile stacking is based on the forcing the sample zone out of the capillary with simultaneous application of the separation voltage. Under such conditions, the enhancing factor achieves the value 57 for peak area compared to the small sample injection length (3.2 mm, hydrodynamic pressure impulse 150 mbar.s). A fluorescence detector with a broad excitation filter (240–400 nm) and an emission filter (495 nm) was used for visualisation of the native fluorescence of perampanel. The calibration dependence of the method was linear (in the range of 10–1000 ng mL−1), with adequate accuracy (99.8–103.3 %) and precision (13.1%). LOD and LOQ for perampanel were 2.9 ng mL-1 and 9.5 ng mL−1, respectively. Clinical applicability was validated using serum samples from patients treated with perampanel and the results corresponded with reference LC–MS/MS values. Our method offers a promising alternative for determining serum perampanel with several advantages. In particular, the low quantity of serum (25 μL) required means that testing can be performed on samples obtained for monitoring other antiepileptic medications, and thus reduces the test-burden on paediatric patients.

Large magnetoelectric effects mediated by electric-field-driven nanoscale phase transformations in sputtered (nanoparticulate) and electrochemically dealloyed (nanoporous) Fe-Cu films.

Large magnetoelectric effects are observed in as-sputtered (nanoparticulate-like) and electrochemically dealloyed (nanoporous) 200 nm thick Fe-Cu films. Application of positive voltages decreases both the saturation magnetization (MS) and coercivity (HC) of the films, while negative voltages cause the reverse effect (increase of MS and HC). The relative variations are as high as 20% for MS and beyond 100% for HC, both for the as-sputtered and dealloyed states. These changes in magnetic properties are caused by controlled and reversible electric-field-driven nanoscale phase transformations between face-centered cubic (fcc) and body-centered cubic (bcc) structures. These phase transitions are in turn due to selective redox reactions induced by the applied voltage, which can be regarded as a "magnetoionic effect." The controlled tuning of HC and MS with the moderate values of applied voltage, together with the sustainable composition of the investigated alloys (not containing noble metals, as opposed to many previous works on magnetoelectric effects in thin films), pave the way towards the implementation of magnetic and spintronic devices with enhanced energy efficiency and functionalities.

(Invited) Metal-Atom Ionization and Diffusion under Electric Field around Metal/Insulator Interfaces; First-Principles View

Metal/insulator interfaces are essential structures in most of electronic and optical devices, and thus the stability of such interfaces is important for the reliability of devices. It has long been known that the metal atoms in a gate electrode often penetrate into insulators by thermal diffusion during the annealing processes in device fabrication. In addition, metal atoms are ionized and such diffusion is remarkably enhanced under electric fields during device operation. Diffusing metal atoms often produce defect electronic states, promote leakage currents, and cause serious damage in electronic devices, particularly in recent nanoscale devices such as metal nanodot memories. On the other hand, such diffusion behavior is positively utilized to produce metal nanowires in insulators for resistive switching memory applications. However, the microscopic understanding of ionization and diffusion of metal atoms has not been obtained yet. In this work, we employ the first-principles calculations and clarify how metal atoms are ionized and diffuse under electric fields around metal/insulator interfaces. We consider metal/insulator interfaces made of a variety of metals (Al, Ag, Au, Pt, Ta, W, etc) and crystalline/amorphous SiO2. Electronic structures, ionic charges, and adiabatic diffusion potentials of metal atoms are evaluated using the first-principles calculations in the density functional theory. Electric field is applied perpendicular to the interface by supplying positive/negative electric charges to the interface-slab systems.With respect to the ionization, we found that the ionic charge of metal atom in SiO2 changes depending on the distance from the interface [1]. In a 0-6Å region near the interface, the diffusing atom is sharply ionized with leaving the interface. This occurs owing to the breakdown of orbital hybridization between electronic states of metal atom and metal induced gap states (MIGS) of metal electrode [2,3]. When the substrate is changed to semiconducting Si and Sn, this region is extended to 10-15Å. Outside this MIGS-penetration region, on the other hand, the ionic charge of metal atom still varies. This variation occurs due to the electron transfers from diffusing metal atom to not only surrounding SiO2 but also metal electrode. In this way, we can conclude that the ionization of the metal atom first begins quantum mechanically in the MIGS-penetration region and then its ionization charge changes electromagnetically outside the MIGS-penetration region.With respect to the diffusion under electric field, we found that the diffusion barrier linearly decreases with increasing the electric field. This result indicates that the electric field remarkably enhances the metal-atom penetration probability into SiO2, like an exponential function of electric field. Such enhancement works effectively for metal atoms with small electronegativity and mainly in the case of positive voltage application, which is in good agreement with observations. This is because most metal atoms prefer to ionized positively in insulators and small-negativity atoms have large ionic charges. These results are discussed in details, together with reviewing recent experiments, comparing to the cases of metal/semiconductor interfaces, and focusing on the fundamental physics of ionization and diffusion. <references> [1] Y. Asayama et al., Materials Science in Semiconductor Processing, DOI: 10.1016/j.mssp.2016.09.010 (2016). [2] T. Hiramatsu et al., Jpn. J. Appl. Phys. 53, 058006 (2014).[3] S. Sasaki and T. Nakayama, Jpn. J. Appl. Phys. 55, 111302 (2016). Figure 1

Potential-induced degradation of thin-film Si photovoltaic modules

Potential-induced degradation (PID) of thin-film Si photovoltaic (PV) modules was investigated. The characteristics of PID phenomena of thin-film Si PV modules are markedly different from those of crystalline Si PV modules. Not only performance loss but also linear-shape and spot-shape delamination was observed after negative voltage application. Recovery from PID was also observed after positive voltage application. However, rapid progression of PID was found after the second negative voltage application after recovery from the initial PID. The root cause of PID of thin-film Si PV modules is thought to be the delamination between a transparent conductive oxide film and a glass substrate. Such degradation accompanied by delamination was also observed in thin-film Si PV modules exposed outside for about 5 years.

雷インパルス電圧による絶縁被覆電極表面の帯電が絶縁破壊特性に及ぼす影響

Covering an electrode with a dielectric layer improves the performance of SF6 gas-insulated systems. This time, the authors evaluated the influence of charge accumulation of the coated electrode surface on the breakdown characteristics and measured the charge amount on the coated electrode surface. Results of the breakdown voltage measurements showed that, without the charge elimination, both the absolute value and the dispersion of the breakdown voltages enlarged. On the other hand, the influence of the charge accumulation was not observed for the minimum breakdown voltages. By measuring the surface potential of the coated electrode, two results were obtained. First, as for negative voltage application, if the electric field of the coated electrode tip exceeded the critical ionization electric field of SF6 gas, but breakdown did not occur, a positive surface potential was observed. On the other hand, if breakdown occurred, the surface potential hardly changed. Second, as for positive voltage application, if breakdown occurred, a negative surface potential was observed. On the other hand, if breakdown did not occur, the amount of the surface potential varied depending on the electrode system and the SF6 gas pressure.

A power dual-gate laterally-diffused MOSFET on 4H–SiC

ABSTRACTA power dual-gate LDMOSFET (DG-LDMOS) structure with better electrical characteristics is presented on 4H–SiC. In the new device, one gate is on the SiC surface whereas other gate is placed in a trench. Simultaneous application of positive voltage to both the gates in DG-LDMOS forms two channels which conduct output current in parallel for positive drain voltages. This enhances the output current (ID) and transconductance (gm) and leads to higher cut-off frequency (fT). The reduced-surface-field effect is improved by placing trenches in the drift layer to increase blocking voltage (Vbr). For drift layer doping of 4 × 1016 cm−3, the new device gives a Vbr of 301 V with fT of 14.1 GHz. Our two-dimensional simulations show that the DG-LDMOS can provide 90% higher ID, 65% increase in gm, 78% higher fT and 72% improvement in Vbr when compared to the conventional counterpart with identical doping and cell length.

Analysis of interfacial energy states in Au/pentacene/polyimide/indium–zinc-oxide diodes by electroluminescence spectroscopy and electric-field-induced optical second-harmonic generation measurement

By using electroluminescence (EL) spectroscopy and electric-field-induced optical second-harmonic generation (EFISHG) measurement, we analyzed interfacial energy states in Au/pentacene/polyimide/indium–zinc-oxide (IZO) diodes, to characterize the pentacene/polyimide interface. Under positive voltage application to the Au electrode with reference to the IZO electrode, the EFISHG showed that holes are injected from Au electrode, and accumulate at the pentacene/polyimide interface with the surface charge density of Qs = 3.8 × 10−7 C/cm2. The EL spectra suggested that the accumulated holes are not merely located in the pentacene but they are transferred to the interface states of polyimide. These accumulated holes distribute with the interface state density greater than 1012 cm−2 eV−1 in the range E = 1.5–1.8 and 1.7–2.4 eV in pentacene and in polyimide, respectively, under assumption that accumulated holes govern recombination radiation. The EL–EFISHG measurement is helpful to characterize organic–organic layer interfaces in organic devices and provides a way to analyze interface energy states.

The effects of an external electric field on the dynamics of cold plasma jets—experimental and computational studies

Atmospheric pressure plasma jets provide a convenient and stable means to transport highly reactive plasma species beyond the confines of the plasma generating electrodes and into the ambient air; such characteristics make them an ideal tool for many emerging plasma processing applications. As the guided streamer exits the jet capillary, the application of an external electric field can significantly influence the dynamics of propagation, potentially providing a means to manipulate the transport of plasma species to a downstream substrate. In this paper the influence of positive and negative voltages pulses applied to an external electrode situated along the axis of streamer propagation is examined experimentally and computationally using a simplified 1.5D model. It is shown that application of a positive voltage pulse to the external electrode reduces the velocity of propagation of the cathode-directed streamer and the application of a negative voltage pulse increases the velocity of propagation. Further to this, the application of high positive voltages to the external electrodes effectively inhibits propagation and results in a significant decrease in the emission intensity from excited states populated by energetic electrons. The results obtained experimentally are compared and contrasted with those from the computational model to uncover the underlying physical mechanisms at play.

FDTD Simulation of Lightning Surges on Overhead Wires in the Presence of Corona Discharge

A simplified model of corona discharge for finite-difference time-domain (FDTD) computations has been applied to analyzing lightning surges propagating along overhead wires with corona discharge. The FDTD computations simulate the experiments of Inoue and Wagner . In Inoue's experiment, a 12.65-mm radius, 1.4-km-long overhead wire was employed, and in Wagner 's experiment, a 21- or 25-mm radius, 2.2-km-long overhead horizontal wire was employed. The critical electric field on the surface of the 12.65-mm-radius wire for corona initiation is set to E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> = 1.4, 2.4, or 2.9 MV/m, and those for 21- and 25-mm-radius wires are set to E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> = 2.2 and 2.1 MV/m, respectively. The critical background electric field for streamer propagation is set to E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cp</sub> = 0.5 MV/m for positive voltage application and E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cn</sub> = 1.5 MV/m for negative voltage application. The FDTD-computed waveforms (including wavefront distortion and attenuation at later times) of surge voltages at three different distances from the energized end of the wire agree reasonably well with the corresponding measured waveforms. Also, the FDTD-computed waveforms of surge voltages induced on a nearby parallel bundled conductor agree fairly well with the corresponding measured waveforms.

A Simplified Model of Corona Discharge on Overhead Wire for FDTD Computations

A simplified model of corona discharge on overhead wire has been proposed for propagating surge computations using the finite-difference time-domain method. The radial progression of corona streamers from the wire is represented as the radial expansion of cylindrical conducting region whose conductivity is several tens of microsiemens per meter. Two wire radii are considered: 5 and 2 mm, in order to simulate two experimental con- figurations by Noda. The critical electric field on the surface of a 5-mm radius wire for corona initiation is set to E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> = 1.8 or 2.9 MV/m. For a 2-mm radius wire, it is set to E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> = 2.2 MV/m. The critical background electric field necessary for streamer propagation is set to E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cp</sub> = 0.5 MV/m for positive voltage application, and E <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">cn</sub> = 1.5 MV/m for negative voltage application. The computed waveform of radial current (including both conduction and displacement currents) agrees well with the corresponding measured waveform. Also, the computed relation between the total charge (charge residing on the wire and emanated corona charge) and applied voltage (qV curve) agrees well with the corresponding measured one, except for relatively low applied voltages. Additionally, the increase of coupling between the energized wire and another one nearby due to corona discharge is well reproduced.

An Electrostatic Model for DNA Surface Hybridization

DNA hybridization at surfaces is a crucial process for biomolecular detection, genotyping, and gene expression analysis. However, hybridization density and kinetics can be strongly inhibited by electric fields from the negatively charged DNA as the reaction proceeds. Here, we develop an electrostatic model to optimize hybridization density and kinetics as a function of DNA surface density, salt concentrations, and applied voltages. The electrostatic repulsion from a DNA surface layer is calculated numerically and incorporated into a modified Langmuir scheme, allowing kinetic suppression of hybridization. At the low DNA probe densities typically used in assays (<1013/cm2), electrostatics effects are largely screened and hybridization is completed with fast kinetics. However, higher hybridization densities can be achieved at intermediate DNA surface densities, albeit with slower kinetics. The application of positive voltages circumvents issues resulting from the very high DNA probe density, allowing highly enhanced hybridization densities and accelerated kinetics, and validating recent experimental measurements.

Study on Threshold Behavior of Operation Voltage in Metal Filament-Based Polymer Memory

In the metal filament formation-based organic memory, the positive voltage application over the threshold electric field strength (170 MV/m) is necessary for the filament formation in Cu/P3HT/Al device. By the positive voltage application, the copper ions are generated and drifted into polymer layer, which is clearly confirmed by the secondary ion mass spectroscopy. Also, the field strength (100 MV/m) required for the drift process could be independently determined with a new pulse operation method. We could conclude that the threshold field strength of 170 MV/m was determined by the ionization process of copper. Furthermore, the dependence of the positive field strength and the temperature on the memory behavior was studied.

プリント配線板ファインパターン導体間の耐サージ特性

The flashover voltages (FOVs) between foil conductors across a narrow gap on a printed wiring board with or without backing electrode were measured by four institutions using the same testing boards. The experiments were carried out in air at a room temperature and 40-55%RH. FOVs with two different configurations of the foil conductors on the board were measured. The gap distances studied ranged from 20μm to 200μm, and the thickness of the foil conductor on the board was 6μm or 18μm. The board thicknesses studied were from 60μm to 800μm. FOV was measured under the impulse voltage application (1.2/50μs). The dependences of FOV upon gap distance, polarity of applied voltage, the board thickness and foil thickness were clarified and discussed mainly comparing with calculated results of electric field. The following results are obtained commonly by the four institutions: When the gap distance is smaller than 50μm, FOV is almost independent of the existence of the backing electrode and the board thickness; FOV is independent of the thickness of the foil conductors; When the board thickness is 60μm, FOV is almost unchanged with the increase in the gap distance; FOV at positive voltage application is higher than that at the negative application.