Vertical structured Gallium nitride (GaN) p-n junction diodes with improved breakdown properties have been demonstrated using high-k dielectric passivation underneath the field plate. Simulation results at a reverse voltage of 1 kV showed that the maximum electric field near the mesa-etched p-n junction edges covered with film of dielectric constant k = 10 was reduced to 2.0 MV/cm from 3.0 MV/c...

A theory of integer quantum Hall effect(QHE) in realistic systems based on von Neu-mann lattice is presented. We show that the momentum representation is quite useful and that the quantum Hall regime(QHR), which is defined by the propagator in the momentum representation, is realized. In QHR, the Hall conductance is given by a topological invariant of the momentum space and is quantized exactly...

We analyze broadband electromagnetic measurements of pulse sequences occurring prior to first return strokes of negative cloud-to-ground lightning flashes. Signals generated by lightning discharges were recorded close to the thunderstorm by a magnetic field receiver and traveled up to 600km to three distant electric field receivers. We found that amplitudes of observed preliminary breakdown pul...

For integrated passive device (IPD) applications, we have successfully developed and characterized metalinsulator-metal (MIM) capacitors with 2000 Å plasma-enhanced chemical vapor deposition (PECVD) silicon nitride which are deposited with the SiH4/NH3 gas mixing rate, working pressure, and RF power of PECVD at 250oC. Five PECVD process parameters are designed to lower the refractive index and ...

A 3-terminal breakdown voltage of 2.3 kV has been achieved on an AlN/GaN heterostructure grown on silicon (111) substrate using an optimized local substrate removal. The epitaxy was grown by metal organic chemical vapor deposition with a total buffer thickness of 5.5 μm. In order to suppress the parasitic substrate conduction phenomena under high electric field, the Si substrate has been locall...

Streamer discharges are a primary mode of electric breakdown in thunderstorms and high voltage technology; they are generally believed to grow along electric field lines. However, we here give experimental and numerical evidence that streamers can propagate nearly perpendicularly to the background electric field. These streamers are guided by pre-ionization that is orders of magnitude lower tha...

Nowadays, the most widely used insulating materials in high voltage equipment such as cables are polymeric insulations due to the numerous merits they possess with regards to electrical performance compared to paper insulations. However, electrical treeing, one of the dielectric pre-breakdown phenomena, has been considered as a major contribution to the failure of insulating polymeric materials...

We introduce a theoretical model to investigate the electric breakdown of a substrate on which highly conducting particles are adsorbed and desorbed with a probability that depends on the local electric field. We find that, by tuning the relative strength q of this dependence, the breakdown can change from continuous to explosive. Precisely, in the limit in which the adsorption probability is t...

Ion thrusters are being designed for long-term operation at power, specific impulse, and thrust levels of up to 29 kW, 7000 seconds, and 0.64 N, respectively. The total propellant throughput goal of these thrusters is nearly 100 kg/kW, which corresponds to ~100 khr of operation. Carbon-based grids have been chosen as the baseline design to achieve this propellant throughput and life time goal. ...

There is an increasing interest in the study of direct plasma generated in liquid/ bioliquid as it fi nds more applications in both industry and academic research. For all the applications, it is important to get a better understanding of the key physical mechanisms of the breakdown process. In the present paper, streamer propagation during an electric breakdown process of dielectric liquid was...