INCREASING THE ENERGY EFFICIENCY OF THERMOCATHODES OPERATION

2021 ◽  
pp. 164-168
Author(s):  
Pavel Topala ◽  
Guzgan Dorin ◽  
Alexandr Ojegov
Keyword(s):  
Energy Efficiency ◽  
Cathode Surface ◽  
Discharge Plasma ◽  
Active Surface ◽  
Active Area ◽  
Saturation Current ◽  
Electric Discharge Machining ◽  
Current Voltage ◽  
Metal Cathode ◽  
Current Voltage Characteristics

The paper presents the results of experimental research on modifying the active area of cathode surfaces applied in the construction of electronic guns and increasing their operating efciency. The intensity of the thermo-electronic emission current is directly proportional to the area of the active surface of the cathodes used for this purpose. To change the micro-geometry of the metal cathode surface, the method of pulsed electric discharge machining (PEDM) was applied. As a result of the application of the discharge plasma on the surface of the cathodes, Taylor cones with heights ranging from 50 to 100 µm were extracted. The analysis of the obtained current-voltage characteristics allows us to compare the values of the saturation current intensities for unprocessed cathodes and those processed by the proposed technology. The increase of the active area of the cathodes with conical asperities causes the increase of the electronic thermoemission current by 10^4. A comparing to the cathodes whose active surfaces have not been processed by this method.

Temperature dependence of current-voltage characteristics in μc-Si:H and pm-Si:H PIN structures

2012 ◽  
Vol 1426 ◽  
pp. 365-370
Author(s):  
Francisco Temoltzi Avila ◽  
Andrey Kosarev ◽  
Ismael Cosme ◽  
Mario Moreno ◽  
P. Roca y Cabarrocas
Keyword(s):  
Temperature Dependence ◽  
Temperature Change ◽  
Ideality Factor ◽  
Dark Current ◽  
Series Resistance ◽  
Equivalent Circuit Model ◽  
Saturation Current ◽  
Current Voltage ◽  
Current Voltage Characteristics

ABSTRACTThe dark current-voltage characteristics of PIN structures are studied and analyzed for PV samples as for integral device without taking account the performance of the different elements typically used in equivalent circuit model such as diode n-factor, shunt and series resistances. The contribution of all these elements is very important in the development of devices because they determine the performance characteristics. In this work we have studied and compared the temperature dependence of current-voltage characteristics in μc-Si:H and pm-Si:H p-i-n structures having approximately the same efficiencies with emphasis on their different electronic characteristics such as shunt (Rsh) and series (Rs) resistance, ideality factor (n), and the saturation current (Is), which give us some ideas on role of these elements. In the pm-Si:H cell it was observed that the Rs increases with the increase of the temperature in contrast to the μc-Si:H structures, where the series resistance reduces with temperature change from T = 300 up to 480K. In both the pm-Si:H and μc-Si:H samples Rshreduces with temperature change from 300 up to 480 K. The ideality factor in the pm-Si:H structure shows an increase, and in μc-Si:H a reduction, when temperature increases. Saturation current in both cases increases with temperature as it was expected. From the saturation current it was obtained the build-in potential. Analysis behavior of both saturation current and n-factor with temperature shows that build-in potential increases with temperature in the pm-Si:H, but reduces in μc-Si:H structure.

MODELING OF COAXIAL CARBON NANOTUBE SCHOTTKY DIODES

2010 ◽  
Vol 24 (17) ◽  
pp. 1883-1890
Author(s):  
ALIREZA KARGAR
Keyword(s):  
Carbon Nanotube ◽  
Field Effect Transistors ◽  
Schottky Diodes ◽  
Gate Insulator ◽  
Saturation Current ◽  
Electrical Parameters ◽  
Single Walled Carbon Nanotube ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
P Type

A carbon nanotube (CNT) Schottky diode based on coaxial geometry is presented. We show that coaxially gated CNT field effect transistors (FETs) with a p-type semiconducting single-walled carbon nanotube (s-SWNT) and asymmetric contacts can provide good diode characteristics. The effect of different physical and electrical parameters such as gate bias voltage, gate insulator thickness, and CNT diameter on the rectification current–voltage characteristics is investigated. We demonstrate that it is possible to tune the rectification characteristic, threshold voltage, reverse saturation current, and reverse turn-on voltage by using these parameters.

Temperature Dependent Current-Voltage Characteristics of n-Type β-FeSi2/Intrinsic Si/p-Type Si Heterojunctions

2015 ◽  
Vol 1120-1121 ◽  
pp. 435-439
Author(s):  
Nathaporn Promros ◽  
Dalin Prajakkan ◽  
Nantharat Hongsa ◽  
Nattanee Suthayanan ◽  
Phongsaphak Sittimart ◽  
...  
Keyword(s):  
Current Density ◽  
Ideality Factor ◽  
Series Resistance ◽  
Linear Part ◽  
Thermionic Emission ◽  
Saturation Current ◽  
Current Voltage ◽  
Saturation Current Density ◽  
Current Voltage Characteristics ◽  
P Type

In this work, n-type β-FeSi2/intrinsic Si/p-type Si heterojunctions were prepared by facing-targets direct-current sputtering. We measured their current-voltage characteristics at low temperatures ranging from 300 K down to 50 K and investigated their ideality factor, saturation current and series resistance using thermionic emission theory and Cheung’s method. From thermionic emission theory, the ideality factor and saturation current density were calculated from the slope of the linear part from the forward lnJ-V and the straight line intercept of lnJ-V at zero voltage, respectively. When the temperature decreased from 300 K down to 50 K, the ideality factor increased from 1.12 to 11.13, whereas the saturation current density decreased from 2.09 × 10-6 A/cm2 to 1.06 × 10-9 A/cm2. Using Cheung’s method, we plotted the relations of dV/d(lnJ)-J and H(J)-J in order to estimate the series resistance from the slope of both plots. In addition, we estimated the ideality factor from a y-axis intercept of the dV/d(lnJ)-J plot. The series resistances from both plots were consistent with each other and increased with the decreasing temperature. The ideality factor estimated by Cheung’s method was in agreement with that obtained from estimation by thermionic emission theory.

scholarly journals Экспериментальные исследования таунсендовского разряда с многоострийным катодом на динамической платформе из магнитоуправляемых частиц Fe и Fe-Al

2021 ◽  
Vol 91 (8) ◽  
pp. 1276
Author(s):  
И.А. Шорсткий ◽  
N. Yakovlev
Keyword(s):  
Field Strength ◽  
Discharge Current ◽  
Atmospheric Pressure ◽  
Cathode Surface ◽  
Electrode Gap ◽  
Current Voltage ◽  
Average Electric Field ◽  
Current Voltage Characteristics ◽  
Townsend Discharge ◽  
Discharge Gap

Experimental results of the Townsend discharge in the air gap and atmospheric pressure from a multi-pin cathode based on a dynamic platform of magnetically controlled Fe and Fe-Al particles presented. Dynamic platform method formation from magnetically controlled particles for cathode surface presented. The current-voltage characteristics are obtained for various configurations of the cathode design (with a flat electrode without magnetically controlled particles, with a multi-pin cathode with magnetically controlled Fe or Fe-Al particles), as well as with the presence of a heated spiral in the electrode gap. The use of a multi-pin cathode based on the dynamic platform of magnetically controlled Fe and Fe-Al particles allows to maintain the average electric field strength in the discharge gap and to increase the spark discharge current.

scholarly journals DEVELOPING MANUFACTURING TECHNOLOGY OF COMPOSITE CATHODES WITH METHOD OF PRESSING PYROLYTIC GRAPHITE WITH TRIPLE CARBONATE

2018 ◽  
Vol 59 (8) ◽  
pp. 81
Author(s):  
Svyatoslav V. Lobanov ◽  
Ivan A. Fedorov ◽  
Evgeniy P. Sheshin
Keyword(s):  
Cathode Surface ◽  
Pyrolytic Graphite ◽  
Composite Cathode ◽  
Manufacturing Technology ◽  
Surface Processing ◽  
Field Emission Current ◽  
Current Voltage ◽  
Composite Cathodes ◽  
Current Voltage Characteristics

In this work a manufacturing technology for a composite cathode is described. In this cathode draphite and emission-active substance forms intercalated chemical compound. These cathodes were studied in a mode of field thermo electrone emission at temperatures of 0-1100 ° C and anode voltages of 1 – 15 kV. The article contains results of determination of optimal pressing parameters, different methods of cathode surface processing and field emission current-voltage characteristics.

scholarly journals Modeling of the Channel Thickness Influence on Electrical Characteristics and Series Resistance in Gate-Recessed Nanoscale SOI MOSFETs

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
A. Karsenty ◽  
A. Chelly
Keyword(s):  
Room Temperature ◽  
Series Resistance ◽  
Electrical Characteristics ◽  
Saturation Current ◽  
Mobility Degradation ◽  
Current Voltage ◽  
Voltage Dependent ◽  
Channel Thickness ◽  
Current Voltage Characteristics ◽  
First Time

Ultrathin body (UTB) and nanoscale body (NSB) SOI-MOSFET devices, sharing a similar W/L but with a channel thickness of 46 nm and lower than 5 nm, respectively, were fabricated using a selective “gate-recessed” process on the same silicon wafer. Their current-voltage characteristics measured at room temperature were found to be surprisingly different by several orders of magnitude. We analyzed this result by considering the severe mobility degradation and the influence of a huge series resistance and found that the last one seems more coherent. Then the electrical characteristics of the NSB can be analytically derived by integrating a gate voltage-dependent drain source series resistance. In this paper, the influence of the channel thickness on the series resistance is reported for the first time. This influence is integrated to the analytical model in order to describe the trends of the saturation current with the channel thickness. This modeling approach may be useful to interpret anomalous electrical behavior of other nanodevices in which series resistance and/or mobility degradation is of a great concern.

The Features of the Current-Voltage Characteristics of Field Emission Metal Cathode Covered by a Nanometer Oxide Layer

2016 ◽  
Vol 247 ◽  
pp. 47-53 ◽  
Author(s):  
Vladimir A. Bespalov ◽  
Nikolay A. Djuzhev ◽  
Maksim A. Makhiboroda ◽  
Gleb D. Demin
Keyword(s):  
Oxide Layer ◽  
Field Emission ◽  
Electric Fields ◽  
Electron Model ◽  
Current Increase ◽  
Current Voltage ◽  
Free Electron Model ◽  
Metal Cathode ◽  
Natural Oxide ◽  
Current Voltage Characteristics

Based on the Sommerfeld free-electron model, the specifics of field emission from metal cathode covered by nanometer oxide layer into vacuum was theoretically studied by the example of systems «W-WO3-vacuum» and «Al-Al2O3-vacuum». The significant influence of natural oxide on the current-voltage (CV) characteristics in the region of strong electric fields (more than 107 V/cm) was investigated, where the transition to the faster current increase in the terms of Fowler-Nordheim (FN) coordinates occurs. At low electric fields (less than 107 V/cm) the CV characteristics may be described by the FN formula for the emission current and can be used to estimate the effective barrier height, which is important in selecting a good cathode material.

scholarly journals STUDYING CO₂ CONVERSION IN DC GLOW DISCHARGE

2020 ◽  
pp. 179-184
Author(s):  
V.A. Lisovskiy ◽  
S.V. Dudin ◽  
P.P. Platonov ◽  
V.D. Yegorenkov
Keyword(s):  
Energy Efficiency ◽  
Glow Discharge ◽  
Conversion Coefficient ◽  
Specific Energy Input ◽  
Positive Ions ◽  
Current Voltage ◽  
Co Conversion ◽  
Current Voltage Characteristics ◽  
Gas Molecules ◽  
Gas Supply

We have registered the mass-spectra of the gas mixture leaving the chamber and the discharge current-voltage characteristics and determined the specific energy input (SEI), the absolute conversion coefficient χ and the conversion energy efficiency η in the CO₂ pressure range of 0.05...5 Torr. Converting CO₂ molecules was performed in the glow discharge in a chamber with distributed same-side gas supply and pumping. As a result the conversion coefficient χ equaling 70% was achieved, but the conversion energy efficiency η did not exceed 1...3 % because of considerable power loss due to acceleration of positive ions, gas and electrode heating as well as to inelastic collisions between electrons and gas molecules not leading to CO₂ conversion.

Modification of current-voltage characteristics of planar organic systems by nm-thick copper phthalocyanine or perylene dye interlayer

Open Physics ◽  
2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Ryszard Signerski ◽  
Grażyna Jarosz
Keyword(s):  
Dark Current ◽  
Copper Phthalocyanine ◽  
Photovoltaic Effect ◽  
Saturation Current ◽  
Strong Reduction ◽  
Organic Systems ◽  
Voltage Polarity ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Perylene Dye

AbstractThe effect of a nm-thick interlayer of copper phthalocyanine (CuPc) or perylene dye (MePTCDI) on currentvoltage characteristics of planar organic systems is discussed in this work. The MePTCDI layer in the ITO/MePTCDI/CuPc/Au system strongly reduces reverse dark current by blocking injection of holes from ITOinto CuPc leading to high values of rectification ratio. The CuPc interlayer in the ITO/CuPc/MePTCDI/Ag system causes a strong reduction in electron injection from ITOand reverses a forward polarity. Modification of current-voltage characteristics of illuminated systems with an interlayer of MePTCDI or CuPc is associated with a strong photovoltaic effect. This results from efficient excition dissociation at the CuPc/MePTCDI interface. Saturation current, determined by this process of charge carrier photogeneration, can be observed at particular voltage polarity.

scholarly journals The Ambient Temperature Effect on Current-Voltage Characteristics of Surface-Passivated GaN-Based Field-Effect Transistors

2004 ◽  
Vol 9 ◽  
Author(s):  
W.L. Liu ◽  
V.O. Turin ◽  
A.A. Balandin ◽  
Y.L. Chen ◽  
K.L. Wang
Keyword(s):  
Ambient Temperature ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Saturation Current ◽  
Device Structure ◽  
Ambient Temperatures ◽  
Current Voltage ◽  
Heterostructure Field Effect Transistors ◽  
Current Voltage Characteristics ◽  
Gan Heterostructure

We have studied experimentally the effect of ambient temperature on performance of the surface-passivated Al0.2Ga0.8N/GaN heterostructure field-effect transistors in the temperature range from 25°C to 250°C. The measured data have been compared with physics-based modeling of the GaN transistor characteristics under different ambient temperatures. The experimental data, showing about 33% degradation in the saturation current with a temperature increase from 25°C to 250°C, agrees well with the results of simulations performed using ISE DESSIS software. Obtained results and analytical extrapolations can be used for predicting device performance in changing environments, as well as for optimization of the device structure.

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