• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.05a
• /
• pp.7-10
• /
• 2007

The electron charging and degradation of anode phosphor layers are showed major problems in high electric field with anode electrode of field emission devices. An Al metal layer on the phosphor layer may get rid of these problems. This Al metal layer are formed with the roughness of phosphor surface layer without interlayer and cannot be given rise to enhance the luminance efficiency. In order to enhance the brightness, an anode layer need to be flated between phosphor layer and Al metal layer in anode electrode. After optimizing the anode phosphor layer, an anode layer with Al metal and inter layer increased the brightness and luminescence efficiency 1.5 times more than only phosphor layer in anode.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2008.05a
• /
• pp.29-32
• /
• 2008

The electron charging and degradation of anode phosphor layers are showed major problems in high electric field with anode electrode of field emission devices. An AI metal layer on the phosphor layer may get rid of these problems. This Hetero-metal-oxide phosphor layer are formed with the roughness of phosphor surface layer without interlayer and cannot be given rise to enhance the luminance efficiency. In order to enhance the brightness, an anode layer need to be flated between phosphor layer and AI metal layer in anode electrode. After optimizing the anode phosphor layer, an anode layer with AI metal and inter layer increased the brightness and luminescence efficiency 1.2 times more than only phosphor laver in anode.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.05a
• /
• pp.90-93
• /
• 1996

The conduction mechanisms of the off-current in low temperature ($\leq$600$^{\circ}C$) processed polycrystalline silicon thin film transistors (LTP poly-Si TFT's) has been systematically studied. Especially, the temperature and bias dependence of the off-current between unpassivated and passivated poly-Si TFT's was investigated and compared. The off-current of unpassivated poly-Si TFT's is due to a resistive current at low gate and drain voltage, thermal emission current at high gate, low drain voltage, and field enhanced thermal emission current in the depletion region near the drain at high gate and drain voltage. After hydrogenation, it was observed that the off-currents were remarkably reduced by plasma-hydrogenation. It was also observed that the off-currents of the passivated poly-Si TFT's are more critically dependent on temperature rather than electric field.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.5
• /
• pp.396-400
• /
• 2005

Carbon nanotubes (CNTs) have been well known as electron emitters for field emission applications like FEDs. In this work, we propose as new application a vacuum sensor using CNTs and discuss its current-voltage characteristics as a function of vacuum pressure. The proposed sensor, based on electrical discharge theories in air gap well-known as Townsend theory and as Paschen's law, works by figuring out the variation of the dark current and the initial breakdown voltage depending on the vacuum pressure of air which can ionize through collisions with the electrons accelerated by high electric field.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.13 no.3
• /
• pp.265-272
• /
• 2000

In this paper the corona discharge in SF$_{6}$ gas used as insulating material in lots o high voltage equipment, is simulated by finite element method with Flux-Corrected Transport(FCT) method. By application of proposed method the negative corona discharge characteristics in needle to plane electrode is analyzed with time step. For the accuracy of analysis the secondary electron emission by photon and ion are also considered as well as the accuracy of analysis the secondary electron emission by photon and ion are also considered as well as townsend first ionization and electron attachment. The calculated results show that the electric field intensity between anode and ion group is decreased as times go-by according to field distortion by those space charge. Accordingly the electron density is decreased strongly by the attatchment effect of SF6 gas so that the corona discharge becomes extinguished abruptly.y.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1997.11a
• /
• pp.270-274
• /
• 1997

The numerical model that can describe the ignition of the pseudospark discharge using hybrid fluid-particle method has been developed. The evolution process of the discharge has been divided into four phases along the potential distribution. After the plasma enters in the hollow cathode, the confining effect which is one of hollow cathode properties occurs and the electron current on anode rises rapidly. As the plasma expands successively, the sheath contracts and as the electric field in the sheath increases, the field-enhanced thermionic emission(Schottky emission) occurs. From numerical results, the physical mechanism that causes the rapid current rise in the ignition of the pseudospark discharge could be identified.

• Fire Science and Engineering
• /
• v.33 no.2
• /
• pp.30-38
• /
• 2019

Tracking, which is one of the main causes of electrical fires, is perceived as a physical phenomenon of electrical discharge. Hence tracking should be explained based on electric field analysis, conduction path by electron generation, and gas discharge physics. However, few papers have considered these details. This paper proposes a tracking mechanism including their effects on tracking progress. In order to prove this mechanism, a tracking experiment, an electric field analysis for the carbonization evolution model, and an explanation of the tracking process by gas discharge physics were conducted. From the tracking experiment, the current waveforms were measured at each stage of the tracking progress from corona discharge to tracking breakdown. The electric field analysis was carried out in order to determine the electric field on the surface of a dry-band and the high electric field region for electron generation during the generation and progress of carbonization. In this paper, the proposed tracking mechanism consisted of six stages including electron avalanche by corona discharge, accumulation of positive ions, expansion of electron avalanche, secondary electron emission avalanche, streamer, and tracking by conductive path. The pulse current waveforms measured in the tracking experiment can be explained by the proposed tracking mechanism. The results of this study will be used as the technical data to detect tracking phenomenon, which is the cause of electric fire, and to improve the proof tracking index.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2006.05a
• /
• pp.31-34
• /
• 2006

The characteristic of carbon nano fiber (CNF) as electron emitters was described. Carbon nano fiber (CNF) of herringbone was prepared by thermal chemical vapor deposition(CVD), mixed with binders and conductive materials, and then were formed by screen-printing process. In order to increase effectively field emissions, the surface treatment of rubbing & peel-off was applied to the printed CNF emitters on cathode electrode. The measurements of field emission properties were carried out by using a diode structure inline vacuum chamber. CNF of herringbone type showed good emission properties that a turn on field was as low as $2.5V/{\mu}m$ and current density was as large as $0.15mA/cm^2$ of $4.5V/{\mu}m$ with electric field. After the vacuum packaged panel of 5-inch in diagonal, the measured white brightness was as high as $7000cd/m^2$ at 1900V of anode and 700V of gate voltage.

• Journal of Korean Vacuum Science & Technology
• /
• v.3 no.1
• /
• pp.95-97
• /
• 1999

A 3.12" FED panel was packaged successfully using the anode plate on which phosphors and black matrix were coated and cathode plate containing emitter arrays. The vacuum level of the panel was investigated during panel evacuation, tip-off and getter activation process. The packaged panel exhibited vacuum level below 2${\times}$10-6 Torr. Similar experiments were carried out for 10" panel made of bare plates. In addition, the vacuum level of two panels was compared continuously after tip off process; one with the getter and the other without it.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.50 no.8
• /
• pp.419-422
• /
• 2001

This paper presents the principle and fabrication of a novel micro mass spectrometer and emission test of hot electron for ionization. A micro mass spectrometer consists of a micro ion source and a micro ion separator. The micro ion source consists of a hot filament and grid electrodes. Electrons emitted from a hot filament are to ionize some sample molecules. The ions are accelerated to an ion detector by an electric field. Mass can be analyzed by using the time of fight depending on the mass-to-charge ratio. The current of hot electron emission from the hot filament is measured for various input voltages.