Critical Value Of Electric Field Research Articles

2D Amorphous GaOX Gate Dielectric for β-Ga2O3 Metal-Insulator-Semiconductor Field-Effect Transistors

Beta gallium oxide (β-Ga2O3) is an n-type ultra-wide bandgap semiconductor material with a reported bandgap from 4.5 eV to 4.9 eV. β-Ga2O3 is a frontrunner in the research for next-generation power devices owing to its numerous merits including the wide range of donor doping concentrations, large bandgap, high theroretical value of critical electric field (~8 MV/cm) leading to substantial Baliga’s figure of merit of ~1900, and the low production cost for crystalline wafers. The last is enabled by the commercial development of several bulk growth techniques, namely, melt growth methods including Czochralski and edge-defined film-fed growth, and epitaxial growth. The metal-insulator-semiconductor field-effect transistor (MISFETs) is the most widely used device structure since it often requires less complicated fabrication process and offers better device scaling and faster switching speed than their counterparts such as junction field-effect transistors or bipolar junction transistors. Various dielectric materials, such as silicon dioxide, hafnium oxide, and aluminium oxide, have been explored for incorporation into β-Ga2O3 MISFETs. However, many of the dielectrics require high-temperature and/or high-vacuum processes during fabrication. Recent studies have reported on the self-limiting formation of native oxide film on the surface of liquid gallium at room temperature and the application of the oxide film as a passivation or a dielectric layer in a nano-scale device. In this study, two-dimensional (2D) amorphous gallium oxide (a-Ga2O3) film is fabricated through the liquid gallium squeezing technique and is integrated with a β-Ga2O3 field-effect transistor (FET) to demonstrate an a-Ga2O3/β-Ga2O3 MISFET.In this work, β-Ga2O3 nano-flakes were obtained through mechanical exfoliation and were dry-transferred onto Si/SiO2 substrates. Electron-beam lithography and electron-beam evaporation were performed to define and deposit Ti/Au electrodes, respectively, where rapid thermal annealing was performed afterward to form Ohmic source and drain contacts. Polypropylene carbonate (PPC) solution was spin-coated and baked on a polydimethylsiloxane (PDMS) film, placed on a glass slide for mechanical support, to form a uniform PPC layer on the PDMS film. A liquid gallium droplet was placed on the PPC/PDMS film and was squeezed with a cleaned glass slide to form a uniform 2D a-Ga2O3 layer. The fabricated a-Ga2O3 layer was dry-transferred onto a β-Ga2O3 FET during which temperature of 90 °C was applied to the sample chuck to completely release the PPC layer with the a-Ga2O3 layer from the PDMS layer. The resulting a-Ga2O3/β-Ga2O3 FET was submerged in acetone to remove the PPC layer. The above dry-transfer process of the a-Ga2O3 layer was conducted twice to form double-layered a-Ga2O3 on the β-Ga2O3 FET, before performing electron-beam lithography and electron-beam evaporation to respectively define and deposit the Ni/Au top-gate electrode.The electrical properties of the fabricated device is characterized as a Ni/a-Ga2O3/β-Ga2O3 heterojunction and an a-Ga2O3/β-Ga2O3 MISFET at temperatures of 25 °C, 150 °C, and 250 °C. The Ni/a-Ga2O3/β-Ga2O3 heterojunction of the device shows a clear rectification characteristic with a wider operating voltage compared to those of standard Ni/β-Ga2O3 devices in literatures. The double-layered a-Ga2O3 The a-Ga2O3/β-Ga2O3 MISFET exhibits normally-on n-type conductivity with stable operation at temperatures from 25 °C to 250 °C, where the obtained on/off current ratio and mobility range from 5.3×108 to 4.8×107 and 4.7 cm2/V·s to 6.9 cm2/V·s, respectively. The subthreshold swing and the threshold voltage of the a-Ga2O3/β-Ga2O3 MISFET showed increases and negative shifts at higher temperatures, respectively. This work demonstrates the facile fabrication process of the a-Ga2O3/β-Ga2O3 MISFET and its high-temperature stability through the integration of the 2D amorphous Ga2O3 gate dielectrics with a β-Ga2O3 semiconductor.

Numerical simulation of electrokinetic control of miscible viscous fingering

Active control of viscous fingering (VF) is of critical importance for many industrial and experimental systems. Here, we numerically study the electrokinetic control of miscible VF using an externally applied electric field. Simulations for three intrinsically hydrodynamically unstable mobility ratios are carried out using two different configurations for each: case I where the high-viscosity resident fluid has higher electroosmotic mobility than the invading low-viscosity fluid and case II where the resident fluid has a lower electroosmotic mobility than the invading fluid. For both cases, the theoretical critical electric field value required to (de)-stabilize the interface is computed and electric fields around this value are applied in simulations. Qualitative results show that VF can be fully suppressed if an electric field is applied with an absolute value above the critical field strength. For case I, this means an electric field in the direction of the pressure-driven flow, while for case II, a field in opposite direction is required. Our quantitative analysis using interfacial and mixing lengths was used to support the qualitative findings. Even though any field strength applied in the right direction will reduce the instability, full suppression is only achieved if the absolute field strength is higher than the required critical field strength. The results from this work provide useful insights that can be applied to electrokinetically enhanced oil recovery, spreading of pollution zones in aquifers, band broadening in liquid chromatography, and electrokinetic soil remediation.

Structural evolution and thermal runaway of refractory W and Mo nanotips in the vacuum under high electric field from PIC-ED-MD simulations

We performed multiscale-multiphysics simulations for W, Mo and Cu nanotips under high electric field to investigate their structural evolution and thermal runaway process. The critical electric field values for the electric prebreakdown condition are predicted to be 311 MV m−1, 570 MV m−1 and 675 MV m−1 for Cu, Mo and W nanotips respectively (R 0 = 1 nm, H 0 = 100 nm). The boiling point of the metal is found to be a good predictor of the critical electric field strength for the initiation of thermal runaway. For metal nanotips made of refractory metals such as W and Mo, the structural thermal runaway process is determined by the rapid growth of small protrusions and their subsequent sharpening and thinning under the high electric stress on the apex region. On the other hand, the more intense atomic evaporation of Cu metal nanotips is caused by the ejection of large droplets generated by recrystallization and necking of the molten region at the apex of the nanotip. The differences in the observed structural evolutions of nanotips between refractory metals and the Cu during the thermal runaway event clearly show the strong influence of melting and boiling points on the electric prebreakdown process in nanoscale.

First Principles Investigation on Electrically Controlled Magnetic Moments of Ultrathin Palladium Film on MgO(001)

Electric field dependence of magnetic, electronic, and structural properties in a Pd bilayer film on MgO (001) is investigated by using the first-principles electronic structure calculations within density functional theory. We find that, due to the lattice mismatch of 6.7 %, a ferromagnetic ground state is stabilized at zero electric field on an otherwise paramagnetic Pd with the spin magnetic moments of m = 0.31 and 0.34 μB in surface and interface Pd, respectively. The application of an external electric field, E, causes the Pd magnetic moments to be modulated in a site- and electric field-dependent manner. As the external electric field pointing inward to the Pd surface is increased up to the critical value of 1.3 V/Å, the surface Pd moment is barely changed while the interfacial Pd moment increases linearly with E. Above this critical electric field, the moments of both the interfacial and surface Pd atoms exhibit nonlinear increase with E and reach up to 0.34 (surface) and 0.41 (interface) μB at E = 2.5 V/Å. When the electric field direction is inverted, a similar dependence on E is obtained for both Pd atoms at the critical electric field value of -0.5 V/Å. The peculiar behavior of the induced magnetic moments is explained by combining the linearized Stoner and itinerant conduction models. We reveal that this prominent magnetoelectric effect is due to the modulated charge occupancy of Pd 4d-states in the minority spin channel in which the dSUBzSUP2/SUP/SUB and dSUBxSUP2/SUP-ySUP2/SUP/SUB orbitals play crucial roles.

RETROFIT OF OUTDOOR MEDIUM VOLTAGE CIRCUIT BREAKER WITH ECO-FRIENDLY GAS TO REPLACE SF 6

In this paper, some stages of the assessment for the replacement of sulphur hexafluoride (SF6) with the fluoronitrile (C4F7N) and carbon dioxide (CO2) mixture in a medium-voltage vacuum interrupting circuit breaker, HORIZON 38kV Outdoor Circuit Breaker manufactured by BRUSH Switchgear, is presented. The circuit breaker volume is filled with the fluorinated gaseous mixture and tested for both basic lightning impulse and short duration power frequency withstand following the recommendations of the relevant standards. It should be noted that some crucial modifications were made to the design to suit the new gas mixture under test. Prior to the test campaign, a series of electric field computations were performed, using a commercial finite element method (FEM) software package, to ensure that a safety margin from the critical electric field values is maintained and identify areas of excessive electric field stress that can be potentially improved. Data on the properties of the fluoronitrile compound and its mixture with CO2 is presented. Initial test results demonstrate that the more environmentally friendly gaseous mixture of 20% fluoronitrile content offers satisfactory insulation withstand performance, indicating its suitability from an insulation performance perspective.

Prediction of inverse spin Hall devices based on the direct injection of carriers in L-valley of GaAs

Numerical simulations are carried out to estimate the inverse spin Hall voltage (V ISHE) as a function of applied electric field, dopant density and excitation energy for n-GaAs based opto-spintronic devices. Adopting a three valley rate equation model, an expression is derived for the density of spin polarized electrons accumulated in different valleys of conduction band. It is noted that an external electric field can be used to enhance the magnitude of V ISHE significantly, however the shape of curve depends upon the choice of excitation energy. A significant rise of V ISHE is noted beyond a critical value of electric field when the carriers are injected into Γ-valley of GaAs. On the other hand, a peak like behaviour is observed when hot electrons are injected into Γ-valley. A dual slope behaviour of V ISHE with applied electric field is noticed when carriers are injected directly into L-valley of GaAs, where a reasonable value of V ISHE can be predicted even for a modest value of electric field. Further, a peak like behaviour of V ISHE with dopant density is predicted irrespective of the choice of excitation energy. The optimum dopant density of n-GaAs based Inverse spin Hall devices is found to be ∼4 × 1016 cm−3. Theoretical predictions made in this work are critically important for the realization of next generation inverse spin Hall devices involving L-valley electrons.

Предпробойное состояние и его диагностика в многослойных структурах 0.55Pb-Mg-=SUB=-1/3-=/SUB=-Nb-=SUB=-2/3-=/SUB=-O-=SUB=-3-=/SUB=--0.45PbSc-=SUB=-1/2-=/SUB=- Nb-=SUB=-1/2-=/SUB=-O-=SUB=-3-=/SUB=-

Detection of breakdown voltage and diagnostics of the pre-breakdown state of a material is a topical task of studying the characteristics of dielectric materials and structures on their base under applied external electric field. A new efficient method for diagnosing the pre-breakdown state of multilayer structures (MLC) based on the 0.55PbMg1/3Nb2/3O3-0.45PbSc1/2Nb1/2O3 (PMN-PSN) ferroelectric relaxor is considered. The method is based on the analysis of the dynamics of the MLC surface temperature changes upon application of an external electric field. A set of MLC samples was tested under the action of an electric field E = 10 - 120 kV/cm at temperatures from room temperature to 80 ℃. The critical electric field value characterizing the pre-breakdown state and, consequently, limiting the upper level of operating voltages for electrocaloric applications, was determined for PMN-PSN multilayer structures.

(Invited) A New Analysis of the Dependence of Critical Electric Field on Semiconductor Bandgap

Recently there has been much interest in wide- and ultra-wide-bandgap (WBG/UWBG) semiconductors for power conversion, radio-frequency, and other applications. The benefits of these materials for high-power devices ultimately stems from the increase in critical electric field (EC) with increasing bandgap (EG). Most researchers cite the work of Hudgins et al. [IEEE Trans Power Elec. 18, 907 (2003)] which reported that EC ~ EG 2.0 for indirect-gap materials and EC ~ EG 2.5 for direct-gap materials. These dependencies are based on empirical power-law fits to reported experimental data. The exponent in the power-law is critical when predicting the performance of power devices composed of new UWBG materials, since the Unipolar Figure-of-Merit (UFOM) scales as EC 3. This work has re-analyzed old data and also analyzed new data, and has found EC ~ EG 1.8 with no difference between direct- and indirect-gap materials. A theory that explains this dependence has also been derived and shows good agreement with the experimental data. A key point is that the critical electric field is not a constant for a given material. Rather, EC depends on temperature and doping. Further, it is defined for a triangular field distribution, i.e. a non-punch-through (NPT) drift region, not a punch-through (PT) drift region with a trapezoidal field distribution. Careful examination of the literature revealed that critical electric field values have been reported for various doping levels, and that in general no distinction between values derived from PT and NPT structures has been made. Fortunately, in most cases values have been reported at room temperature, which is taken to be standard. As such, we have derived a procedure that allows EC values to be normalized to a fixed doping (1×1016 cm-3) and a NPT field distribution. The method equates the ionization integrals for the non-standard and standard configurations and backs out the values of EC normalized to the standard configuration. Using this algorithm, normalized values of EC for a variety of semiconductors were tabulated and plotted against bandgap. These data are shown in the attached Figure, where a power-law fit yielding an exponent of 1.8 for both direct- and indirect-gap semiconductors is also shown. The conventional semiconductors Ge, Si, InP, GaAs, and GaP are all included. The narrow-gap semiconductors InSb and InAs are not included, as it is believed that breakdown in these materials may have substantial contributions from tunneling, in addition to impact ionization. GaSb is also excluded due to experimental uncertainty. The wide-bandgap semiconductors SiC and GaN are included in the analysis, although considerable debate still exists concerning the critical field of GaN. For the UWBG semiconductors such as Ga2O3, AlN, and diamond, even more uncertainty exists, and only the critical electric field of diamond has been included in the analysis, which is nevertheless subject to large uncertainty. To explain the observed experimental data, a model based on the ionization integral has been derived. In this model, the ionization integral is transformed from an integral over space into an integral over electric field. The ionization rate as a function of field is then inserted into the integral. For this, the lucky-drift model of Ridley is used [J. Phys. C 16, 3373 (1983)]. This model is an extension of the more-commonly-cited lucky electron model first proposed by Shockley. In the extended model of Ridley, elastic momentum relaxation is considered in addition to energy relaxation. The model depends on three input parameters, which are the threshold energy required for ionization (Eth), the mean carrier relaxation length (l), and the ratio of the average energy lost per collision to the threshold energy (r). These parameters all depend on bandgap, with Eth ~ EG, l ~ EG -3/2, and r ~ EG -1. Inserting these dependencies into the ionization integral and numerically extracting the electric field at which avalanche occurs for a given bandgap yields a curve of EC versus EG, which closely matches the experimental EC ~ EG dependence. This work was partially supported by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly-owned subsidiary of Honeywell International Inc, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525. This material is also based upon work supported by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the Assistant Secretary of Defense for Research and Engineering. Figure 1

Electro-rheological investigation on W/O emulsions morphology under electric fields

Five w/o model emulsions were produced using mineral oil, deionized water and Span 80. The samples of higher stability and smaller mean droplet size were produced by increasing surfactant concentration. Critical electric field stability tests were conducted, both using electrocoalescence and electrorheology, to confirm that critical field increases with decreasing droplet size. As direct current field increases, measurements of G'/G" have shown an intersection between these moduli, from which emulsions presented a predominantly elastic behavior. Optical microscopy tests suggested that such crossing point is related to a minimum electric field in which an emulsion effectively undergoes structural changes due to droplets alignment. This minimum alignment field seems to be correlated with the critical electric field once it is approximately half of critical electric field value.

Investigation of the relevant kinetic processes in the initial stage of a double-arcing instability in oxygen plasmas

A numerical investigation of the kinetic processes in the initial (nanosecond range) stage of the double-arcing instability was developed. The plasma-sheath boundary region of an oxygen-operated cutting torch was considered. The energy balance and chemistry processes in the discharge were described. It is shown that the double-arcing instability is a sudden transition from a diffuse (glow-like) discharge to a constricted (arc-like) discharge in the plasma-sheath boundary region arising from a field-emission instability. A critical electric field value of ∼107 V/m was found at the cathodic part of the nozzle wall under the conditions considered. The field-emission instability drives in turn a fast electronic-to-translational energy relaxation mechanism, giving rise to a very fast gas heating rate of at least ∼109 K/s, mainly due to reactions of preliminary dissociation of oxygen molecules via the highly excited electronic state O2(B3Σu−) populated by electron impact. It is expected that this fast oxygen heating rate further stimulates the discharge contraction through the thermal instability mechanism.

Demulsifier assisted film thinning and coalescence in crude oil emulsions under DC electric fields

Electrocoalescence has been considered a most efficient method of crude oil dewatering; however, just electric fields are not enough when dealing with heavy crude oils. In this work we studied effect of asphaltene flocculation and effectiveness of variety of chemical demulsifiers in electrocoalescence of water-in-crude oil emulsions. A parallel plate electrode cell was used to apply linearly rising uniform DC electric field to a thin layer of emulsion and the current running through the emulsion was monitored as an indicator of progress in the coalescence. In the first part of the study, model crude oils were used to investigate the roles of flocculated asphaltenes and flocculation inhibitor in electrocoalescence process. It was observed that the asphaltene flocculation adversely affects the rate of electrocoalescence. Second part compares effectiveness of different chemical demulsifiers in breaking water-in-crude oil emulsions under electric field. The experimental observations suggest that there exist a threshold demulsifier concentration limit and further increasing the concentration does not improve electrocoalescence rate. Also the addition of a demulsifier before dispersion of water results into faster separation as compared to the electrocoalescence in emulsion where the demulsifier was added later. Further, we devised a model for qualitative prediction of film drainage between two demulsifier-laden water–crude oil interfaces under a constant DC electric field. The film thinning rates predicted by the model are consistent with the experimentally measured critical electric field values.

Positive Streamer Simulation in Air Using Finite Element Method

A new methodology for positive streamer process is presented. This process depends on the critical electric field value that required for streamer initiation. So, an accurate computational of the electric field distribution across needle-to-plane gap is required. A finite element method using Comsol Multiphysics program is adopted for this simulation. The streamer path has been considered as a conducting path of 300 micro-meter in length and 30 micro-meter in radius with 10⁸ electrons on its head. The results have been verified with others.

Characterization of Al2O3/4H-SiC and Al2O3/SiO2/4H-SiC MOS structures

Abstract The paper presents the results of characterization of MOS structures with aluminum oxide layer deposited by ALD method on silicon carbide substrates. The effect of the application of thin SiO2 buffer layer on the electrical properties of the MOS structures with Al2O3 layer has been examined. Critical electric field values at the level of 7.5–8 MV/cm were obtained. The use of 5 nm thick SiO2 buffer layer caused a decrease in the leakage current of the gate by more than two decade of magnitude. Evaluated density of trap states near the conduction band of silicon carbide in Al2O3/4H-SiC MOS is about of 1×1013 eV−1cm−2. In contrast, the density of the trap states in the Al2O3/SiO2/4H-SiC structure is lower about of one decade of magnitude i.e. 1×1012 eV−1cm−2. A remarkable change in the MOS structure is also a decrease of density of electron traps located deeply in the 4H-SiC conduction band below detection limit due to using of the SiO2 buffer layer.

Light Leakage Induced by Spontaneous Distortion of the Nematic Director in Bulk Defect Structures

Three director profiles of nematic liquid crystal (NLC) cells are presented to elucidate the mechanism of light leakage induced by some defects hidden in NLC cells. In accordance with Landau-de Gennes theory, we simulated the dynamics of these defect profiles using the 2-D finite-difference iterative method and calculated their transmittance using the Jones calculus. Results show that light leakage induced by these defects is caused by spontaneous azimuthal twisting of the director when no electric field is applied. Spontaneous distortion occurs only in the director field around defects and depends on larger nematic anisotropies. The light leakage intensity in cells I and II differs because of difference in the defect structures of the cells. Regardless of the cell type, light leakage is exacerbated when the surface anchoring strength is nonuniform. Light leakage disappears at a critical value of electric field $E_{c}$ . However, a very strong static electric field $E_{c}^{\ast}$ is necessary to force the light leakage to disappear when the flexoelectric effect is considered.

Electronic properties and modulation of structurally bent BN nanoribbon

Boron nitride nanoribbon (BNNR) is a one-dimensional single layer nano-material with finite width and infinite length. Bent BNNR will show some unique electronic properties because of the rotation of Pz orbit. The software DMOL3 of Material Studio, based on the first principles, can be used to calculate the energy band, and the band gap will change with the bending angle; in the armchair BN nanoribbons the change is more obvious. Band gaps of zigzag BN nanoribbons may change more than those in armchair BN nanoribbons do if the external electric field is also added on the bent BN nanoribbons. When the electric field is increased to a certain value, nanoribbons will transit from semiconductor to metal, and it is important that the corresponding critical electric field value depends on the bending angle. The modulation of electric field on the band gap is also related with the size of nanoribbons; the wider the nanoribbon, the easier the modulation, and the smaller the critical electric field.

PRESSURE CORRECTIONS FOR THE VISCOELASTIC POTENTIAL FLOW ANALYSIS OF ELECTROHYDRODYNAMIC CAPILLARY INSTABILITY

Pressure corrections for the viscoelastic potential flow analysis of capillary instability in the presence of axial electric field has been carried out. In viscoelastic potential flow theory, viscosity enters through normal stress balance and the effects of shearing stresses are completely neglected. We include the viscous pressure in the normal stress balance along with irrotational pressure and it is assumed that this viscous pressure will resolve the discontinuity of the tangential stresses at the interface for two fluids. A dispersion relation is derived for the case of axially imposed electric field and stability is discussed in terms of various parameters such as electric field, Deborah number, Ohnesorge number, permittivity ratio and conductivity ratio etc. Stability criterion is given in terms of critical value of wave number as well as critical value of applied electric field. The system is unstable when electric field is less than the critical value of electric field, otherwise it is stable. It has been found that irrotational shearing stresses have stabilizing effect on the stability of the system.

Characterizing of corona rings applied to composite insulators

In this paper, the electric field stress is investigated for a set of composite insulators. Three designs of such insulators, with different dimensions and shapes, are used to build a model of a composite system. The critical values of electric field are determined for 230kV and 400kV voltage classes. The field is calculated via a set of basic equations, reflecting the influence of several factors such as voltage, material and corona ring parameters on the insulator aging. The impact of corona rings on reducing electric field stress is determined for different voltages and insulator designs using the concept of efficiency. The ring parameters are optimized to determine their impact on reducing the field stress on the insulator. Therefore, a MATLAB-based code is set to cater for a wide range of parameters and to determine the optimal dimensions and locations of such rings. In all studied cases, the Finite Element techniques are used as a simulation tool for analysis, field contour plotting and stress monitoring.

STUDY ON ELECTROHYDRODYNAMIC CAPILLARY INSTABILITY OF VISCOELASTIC FLUIDS IN PRESENCE OF AXIAL ELECTRIC FIELD

Linear viscoelastic potential flow analysis of capillary instability in presence of axial electric field has been studied. A dispersion relation is derived for the case of axially imposed electric field and stability is discussed in terms of various parameters such as electric field, Deborah number, Ohnesorge number, permittivity ratio and conductivity ratio etc. Stability criterion is given in the terms of critical value of wave number as well as critical value of applied electric field. The system is unstable when electric field is less than the critical value of electric field, otherwise it is stable. It has been found that in presence of the electric field the growth rates for viscoelastic fluid are higher than viscous fluid. Various graphs have been plotted for growth rate and critical electric field.

Viscous potential flow analysis of capillary instability with radial electric field

A linear analysis of capillary instability with radial electric field is carried out using viscous potential flow theory. In viscous potential flow, the viscous term in the Navier-Stokes equation vanishes as vorticity is zero but viscosity is not zero. Viscosity enters through normal stress balance in viscous potential flow theory and the tangential stresses are not considered. The effect of gravity and free surface charges at the interface are neglected. A dispersion relation is derived for the case of radially imposed electric field and stability is discussed in terms of various parameters such as Ohnesorge number, permittivity ratio, etc. A condition for neutral stability is obtained and it is given in terms of critical value of electric field. It is observed that the radial electric field has dual effect on the stability of the system corresponding to the values of conductivities and permittivities of the fluids.

Viscous contribution to the pressure for electroviscous potential flow analysis of capillary instability

Viscous contribution for the Viscous Potential Flow (VPF) analysis of capillary instability with axial electric field at the interface of two viscous fluids has been analysed. In VPF, viscosity enters through normal stress balance and the effects of shearing stresses are completely ignored. To include the effect of shearing stresses, viscous pressure is included in normal stress balance along with irrotational pressure and it is assumed that the viscous contribution to the irrotational pressure will resolve the discrepancy between the tangential stresses at the interface. Stability criterion is given in terms of critical value of electric field. Various graphs have been drawn to show the effect of the parameters, such as electric field, inner fluid fraction, Ohnesorge number, conductivity ratio and permittivity ratio.