Papers by Keyword: Electric Field

Abstract: Comprehending the current-voltage properties of CdZnTe device is an essential step toward improving its spectroscopic performance. Thus an in-depth analysis of I-V characteristics on Au/Cd0.9Zn0.1Te/Au device is carried out in this work. Typical non-linear transitions observed in I-V curve are found to be closely correlated with deep donor in CdZnTe. Profile of deep donor ionization probability is calculated under various biases. Afterwards the distribution of space charge and electric field is obtained. Based on these results, reasons for transitions in I-V curve are revealed. Also, related carrier transport mechanisms are confirmed.

Abstract: Investigation on structure and electronic structure under external electric field is a very interesting subject. To investigate the evolution of structure and properties from the perspective of electronic structure, the configuration of NaCl crystal has been calculated with the first principles in different external electric field. The system of energy, bond length, geometrical, radial distribution function, difference charge density, and density of states has been carefully examined. The analysis of the calculated results suggested that, with the increasing of external electric field, the system energy presents the roughly increases to a maximum value then begin to decrease, the long range structure become more disordered, the geometrical structure is significantly influenced, the iconicity of NaCl enhances.

Abstract: We investigated improvement ways of to overcome these reliability issues in a 3.3 kV 4H-SiC DMOSFET. JFET doping with (i) narrow width and (ii) deeper depth than that of the p-well region successfully reduced the electric field in the gate insulator and the on-voltage simultaneously. We achieved a low Ron of 26 mΩcm² at a Vg of +15 V and 150 °C. And highly reliable chips of 0.1 Fit were also achieved both at a positive and negative gate bias of +15 V/ -8 V with MTTF of intrinsic lifetime over 20 years at 3 MV/cm. BTI characterstics both in positive and negative biases also proved reliability over 20 years. The body diode showed stable behavior under forward current operation which is suitable for an external diode-less power module.

Abstract: Chemical composition Pb_0.97La_0.02(Zr_0.75Sn_0.136Ti_0.114)O₃ (PLZST) ceramic was fabricated by conventional solid-state reaction of oxide method. The composition is close to the AFE/FE phase boundary of PLZST ceramic phase diagram. The dependence of remanent polarization of Pb (Zr,Sn,Ti)O₃ ceramic poled under different electric fields on hydrostatic pressure was investigated with special hydrostatic pressure equipment. The results show that PLZST ceramic poled at different DC electric field is metastable state ferroelectric phase. The remanent polarization decreases sharply and is depolarization completely when hydrostatic pressure increases to a bound.

Abstract: In this work, we study the field emission properties of a single vertical carbon nanotube with cathode radius changing. The carbon nanotube is considered as purely perfect conductor, and the anode and cathode are modeled as discs. The radius of anode is kept as 24m, then the radius of cathode is changed from 24 m to 1 m. The emitter of that CNT consists of a hemispherical cap of 4 nm radius (r) on top of a cylinder height of 2 m (h). The distance from anode to cathode is w=h+20m. The overall surface area of the CNT and cathode are all grounded, and the anode plate has a constant potential value of 100 V. The distribution of potential and electric field, field emission current are obtained by simulating with the help of COMSOL Multiphysics 4.3b electrostatics module. We find that with cathode radius decrease, the electric field strength over the surface of carbon nanotube (CNT) strengthening and field emission current increase.

Abstract: Water confined in carbon nanotubes (CNTs) under the influence of an electric field has interesting properties that are potential for nanofluidic-based applications. With molecular dynamics simulations, this work shows that the electric field induces formation of ordered structures of water molecules in the CNTs. Formation of the ordered structures strengthens the electrostatic interaction between the water molecules. As a result, water strongly prefers to fill CNTs over methanol and it produces a separation effect. Interestingly, the separation effect with the electric field does not decrease for a wide range of CNT diameter.

Abstract: The paper deals with modelling of the time varying electric field, applied to composites structures of inorganic materials (containing metal and metal oxide). The structural changes at the initials stages of sintering, characterised by the number of contact per particle and an increase of the areas of interparticle contact have been modelled and examined. The aim of study was estimation of the electric field strength, current density, power losses and forces, acting along the contact area between particles. The field models have been obtained using finite element method and QuickField 5.6 software package.

Abstract: In this paper, analytical modelling and performance analysis of novel device structures such as single gate SOI Tunnel Field Effect transistor (SG SOI TFET), Dual-Material Gate TFET (DMG TFET) and Dual Material Double Gate TFET (DMDG TFET) are proposed. The performance of the three devices is studied and compared in terms of surface potential, electric field and drain current. The DMDG TFET shows better performance in suppressing leakage current and enhancing I_ON current than the SG SOI TFET and DMG TFET. The analytical models of the devices are found to be in good agreement with the results obtained using two-dimensional TCAD device simulator.

Abstract: According to the electromagnetic pump in Magnesium Alloy Casting Experiments Center of University of Science and Technology Liaoning, with the help of ANSYS software, we realized three-dimensional simulation of electric field of the pump by finite element analysis method, and calculated the distribution of electric field generated by five data sets , whose slot length and width were 30mm, 50 mm, 60 mm, 70 mm and 80 mm. We have explored how different runner dimensions affected electric field distribution in electromagnetic field, and simulated the distribution of current density. The optimal size of the runner is 50mm according to the current density distribution.

Abstract: Zinc oxide nanostructures were synthesized by an electrochemical dissolution and deposition process. The zinc plates were immerged in deionized water and used as two electrodes. The process was operated by applying the electric field of 10, 12.5, 25 and 50 V/cm, the constant voltage of 10 V and varied the temperatures from room temperature to 70 °C during 1 h. It was found that the electric field and temperature of electrolyte solution had affected to morphologies of ZnO NSs and were grown in forms of nanoflakes, nanoparticles and nanorods.