• 제목/요약/키워드: Emission current

검색결과 1,497건 처리시간 0.024초

Low Voltage-Driven CNT Cathode and It's Applications

  • Lee, Chun-Gyoo;Lee, Sang-Jo;Cho, Sung-Hee;Chi, Eung-Joon;Lee, Byung-Gon;Jeon, Sang-Ho;Ahn, Sang-Hyuck;Hong, Su-Bong;Choe, Deok-Hyeon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.851-854
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    • 2004
  • By approaching the counter electrode to the CNT emitter, remarkable reduction of the cathode operating voltage has been accomplished in the under-gate CNT cathode structure. The peak emission current density of 2.5 ms/$cm^2$, which is sufficient for high brightness CNT field emission display, was obtained at the cathode-to-gate voltage of 57 V when the CNT-to-counter electrode gap was 2.2 ${\mu}m$. The gate current was less than 10 % of the anode current. The CNT cathode with low driving voltage can help the cost-effective field emission display implemented.

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Fabrication of Sputtered Gated Silicon Field Emitter Arrays with Low Gate Leakage Currents by Using Si Dry Etch

  • Cho, Eou Sik;Kwon, Sang Jik
    • Transactions on Electrical and Electronic Materials
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    • 제14권1호
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    • pp.28-31
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    • 2013
  • A volcano shaped gated Si-FEA (silicon field emitter array) was simply fabricated using sputtering as a gate electrode deposition and lift-off for the removal of the oxide mask, respectively. Due to the limited step coverage of well-controlled sputtering and the high aspect ratio in Si dry etch caused by high RF power, it was possible to obtain Si FEAs with a stable volcano shaped gate structure and to realize the restriction of gate leakage current in field emission characteristics. For 100 tip arrays and 625 tip arrays, gate leakage currents were restricted to less than 1% of the anode current in spite of the volcano-shaped gate structure. It was also possible to keep the emitters stable without any failure between the Si cathode and gate electrode in field emission for a long time.

변형된 게이트 절연막 구조를 갖는 몰리브덴 팁 전계 방출 소자 (Mo-tip Field Emitter Array having Modified Gate Insulator Geometry)

  • 주병권;김훈;이남양
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권1호
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    • pp.59-63
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    • 2000
  • For the Mo-tip field emitter array, the method by which the geometrical structure of the gate insulator wall could be modified in order to improve field emission properties(turn-on voltage and gate leakage current). The device having a gate insulator of complex shape, which means the combined geometrical structure with round shape made by wet etching and vertical shape made by dry etching processes, was fabricated and the field emission properties of the three kinds of devices were compared. As a result, the electric field applied to tip apex could be increased and gate leakage current could be decreased by employing the gate insulator having geometrical wall structure of mixed shape. Finally, the obtained empirical results were analyzed by simulation of electric field distribution at/near the tip apex and gate insulator using SNU-FEAT simulator.

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신재생에너지의 온실가스감축 기여도에 따른 지역별 보급전략 (Regional Supply Strategies for Renewable Energy Sources based on Contribution Level of GHG Emission Reduction)

  • 김현석
    • Current Research on Agriculture and Life Sciences
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    • 제32권4호
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    • pp.215-223
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    • 2014
  • This study examines the contribution level of greenhouse gas(GHG) emission reduction and installation costs of renewable energy facilities. The GHG emission forecasts and industrial structures in the 16 regions of Korea are then analyzed to identify the proper supply of renewable energy sources for each region. The results show that water power is the most effective and efficient renewable energy source to reduce GHG emissions, followed by sunlight, wind power, geothermal heat, and solar heat, respectively. The 16 regions are then categorized into 4 groups based on their GHG emission forecast and industrial structure: high emission and manufacturing group, low emission and manufacturing group, low emission and service group, and high emission and service group. The proper supply of renewable energy sources for each group is then determined based on the contribution level and cost efficiency of GHG emission reduction.

Improved Surface Morphologies of Printed Carbon Nanotubes by Heat Treatment and Their Field Emission Properties

  • Lee, Hyeon-Jae;Lee, Yang-Doo;Cho, Woo-Sung;Kim, Jai-Kyeong;Lee, Yun-Hi;Hwang, Sung-Woo;Ju, Byeong-Kwon
    • Journal of Information Display
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    • 제7권2호
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    • pp.22-25
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    • 2006
  • This paper presents heating process for obtaining standing carbon nanotube emitters to improve field-emission properties from the screen-printed multiwalled carbon nanotube (MWCNT) films. In an atmosphere with optimum combination of nitrogen and air for heat treatment of CNT films, the CNT emitters can be made to protrude from the surface. This allows for high emission current and the formation of very uniform emission sites without special surface treatment. The morphological change of the CNT film by this technique has eliminated additional processing steps, such as surface treatment which may result in secondary contamination and damage to the film. Despite its simplicity the process provides high reproducibility in emission current density which makes the films suitable for practical applications.

감광성 CNT 페이스트의 스크린 프린팅법을 이용한 CNT-FEA의 전계 방출 특성 (Field Emission Characteristics of a CNT-FEA fabricated by Screen-printing of a Photo-sensitive CNT Paste)

  • 권상직;이상헌
    • 한국전기전자재료학회논문지
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    • 제19권1호
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    • pp.75-80
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    • 2006
  • We have fabricated a carbon nanotube field emission display(CNT-FED) panel with a 2 inch diagonal size using a screen printing method and in-situ vacuum sealing technology. The field emission properties of CNT FED panel with square-type CNT emitters. As results, the square-characterized and compared with those of the line-type CNT emitters. As results, the square-type CNT emitters showed much larger emission current and more stable I-V characteristics. Light emission started to be occurred at an electric field of 3.5 V/${\mu}m$ corresponding to the anode-cathode voltage of 700 V. The vacuum level inside of the in-situ vacuum sealed panel was obtained with $1.4 {\times} 10^{-5}$ torr. The sealed panel showed the similar I-V characteristics with the unsealed one and the uniform light emission with very high brightness at a current density of $243 {\mu}A/ cm^2$ obtained by the electric field of 10 V/${\mu}m$.

Field Emission Enhancement by Electric Field Activation in Screen-printed Carbon Nanotube Film

  • Lee, Hyeon-Jae;Lee, Yang-Doo;Cho, Woo-Sung;Kim, Jai-Kyeong;Hwang, Sung-Woo;Ju, Byeong-Kwon
    • Journal of Information Display
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    • 제6권4호
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    • pp.45-48
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    • 2005
  • By applying a critical field treatment instead of the conventional surface treatments such as soft rubber roller, ion beam irradiation, adhesive taping, and laser irradiation, electron emission properties of screen-printed carbon nanotubes (CNTs) were enhanced and investigated based on the emission current-voltage characteristics through scanning electron microscopy. After nanotube emitters were activated at the applied electric-field of 2.5 V/um, the electron emission current density with good uniform emission sites reached the value of 2.13 mA/$cm^2$ , which is 400 times higher than that of the untreated sample, and the turn-on voltage decreased markedly from 700 to 460 V. In addition, enhancement of the alignment of CNTs to the vertical direction was observed.

Performance Evaluation of Early Streamer Emission Lightning Air Terminal

  • Choi, Sang-Won;Her, Yong
    • International Journal of Safety
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    • 제5권2호
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    • pp.18-23
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    • 2006
  • Studies have claimed that ESE (Early Streamer Emission) air terminals offer a vastly increased zone of protection over that of traditional lightning rods (Franklin rods) by causing the emission of an upward streamer/leader: The upward streamer/leader will propagate towards the tip of the downward leader at an early stage in the attachment process.. This paper shows the results of a performance evaluation test of a particular type of the ESE air terminal (called "ElecHippo") with a simple rod tested at the Korea Electrotechnology Research Institute (KERI). The corona emission current of the ElecHippo made by Yong-Jin Enterprise Corp. has also been measured at the Occupational Safety & Health Research Institute (OSHRI). The results show that the ElecHippo meets the French standard of NFC 17-102-1995. The results also verify the ESE performance by measuring the ion emission current generated in the discharge electrode gap as a function of the capacitance and inductance of the equipped devices. Finally, we propose a new method for grounding the system to reduce the lightning damage by combining the ESE air terminal, the early discharge earth plate, the lightning strike recorder and the surge protection device.

$Pb(Zr_{0.56}Ti_{0.44})O_3$ 강유전체 음극의 전극 모형에 따른 전자 방출 특성 (Effect of Electrode Structures on Electron Emission of the $Pb(Zr_{0.56}Ti_{0.44})O_3$ Ferroelectric Cathode)

  • 서민수;홍기민
    • 한국군사과학기술학회지
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    • 제13권4호
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    • pp.699-707
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    • 2010
  • Electric-field-induced electron emission from the three kinds of $Pb(Zr_{0.56}Ti_{0.44})O_3$ ferroelectric cathodes with different electrode structure has been investigated. Regardless of the electrode structures, a threshold field of the each cathode was 2.5-2.6kV/mm, which is 3 times higher than the coercive field of $Pb(Zr_{0.56}Ti_{0.44})O_3$ material. Although the waveform of the electron currents was affected by the structure of the electrode, no significant difference for the emission properties such as the peak current and the pulse width was observed from the three kinds of the cathodes. However, the current density of the cathode was dependent on the electrode structure. From the simulation of electric field distribution, the surface flashover, and the injury region of the cathode surface, it was proved that the prime electrons were initiated at the electrode-ceramic-vacuum triple point by field emission and the emission currents were strongly enhanced by the surface plasma.

Field emission from non-conjugated polymers

  • Ionov, A.N.;Popov, E.O.;Svetlichnyi, V.M.;Nikolaeva, M.N.;Pashkevich, A.A.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.931-932
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    • 2004
  • We investigated a great number of polymer materials. The parameters affecting on its emission properties (namely, film thickness, temperature of polymer preparation. metal substrates and so on) were studied. We observed that emission distributed overfull polymer surface, with current densities up to several hundreds ${\mu}A/cm^2$. Some polymer samples have shown high current emission properties up to 50 ${\mu}A$ in DC and more then 1.5 mA in sinusoidal regimes.

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