• 제목/요약/키워드: Field emission cathode

검색결과 148건 처리시간 0.033초

Simple fabrication process and characteristic of a screen-printed triode-CNT field emission arrays for the flat lamp application

  • Jung, Y.J.;Park, J.H.;Jeon, S.Y.;Park, S.J.;Alegaonkar, P.S.;Yoo, J.B.;Park, C.Y.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1214-1218
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    • 2006
  • We introduced simple fabrication process for field emission devices based on carbon nanotubes (CNTs) emitters. Instead of using the ITO material as a transparent electrode, a metal (Au) with thickness of 5-20nm was used. Moreover, the ITO patterning process was eliminated by depositing metal layer, before the CNT printing process. In addition, the thin metal layer on photo resist (PR) layer was used as UV block. We fabricated the CNT field emission arrays of triode structure with simple process. And I-V characteristics of field emission arrays were measured. The maximum current density of $254{\mu}A/cm2$ was achieved when the gate and the anode voltage was kept 150V and 3000V, respectively. The distance between anode and cathode was kept constant.

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FIELD EMISSION FROM TRIODE FIELD EMITTER WITH PLANAR CARBON-NANOPARTICLE CATHODE

  • Park, Kyung-Ho;Seo, Woo-Jong;Lee, Soon-Il;Koh, Ken-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.309-312
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    • 2002
  • Triode field emitters with planar-carbon-nanopaticle (CNP) cathodes were successfully fabricated using the conventional photolithography and the hotfilament chemical vapor deposition. Electron emission from a CNP triode emitter with a 12-${\mu}m$-diameter gate hole started at the gate voltage of 45 V, and the anode current reached the level of ${\sim}120$ nA at the gate voltage of 60 V, respectively. For the quantitative analysis of the Fowler-Nordheim (F-N) type emission from a CNP triode emitter, we carried out 2dimensional numerical calculation of electrostatic potential using the finite element method. As it turned out, a radial variation of electric field was very important to account for the emission from a planar emitting layer. By assuming the graphitic work function of 5 eV for CNPs, we were able to extract a consistent set of F-N parameters, together with the radial position of emitting sites.

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Fabrication of Transparent Ultra-thin Single-walled Carbon Nanotube Films for Field Emission Applications

  • Jang, Eun-Soo;Goak, Jung-Choon;Lee, Han-Sung;Kim, Myoung-Su;Lee, Nae-Sung
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.353-353
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    • 2008
  • Carbon nanotubes (CNTs) are attractive for field emitter because of their outstanding electrical, mechanical, and chemical properties. Several applications using CNTs as field emitters have been demonstrated such as field emission display (FED), backlight unit (BLU), and X-ray source. In this study, we fabricated a CNT cathode using transparent ultra-thin CNT film. First, CNT aqueous solution was prepared by ultrasonically dispersing purified single-walled carbon nanotubes (SWCNTs) in deionized water with sodium dodecyl sulfate (SDS). To obtain the CNT film, the CNT solution in a milliliter or even several tens of micro-litters was deposited onto a porous alumina membrane through vacuum filtration process. Thereafter, the alumina membrane was solvated by the 3 M NaOH solution and the floating CNT film was easily transferred to an indium-tin-oxide (ITO) glass substrate of $0.5\times0.5cm^2$ with a film mask. The transmittance of as-prepared ultra-thin CNT films measured by UV-Vis spectrophotometer was 68~97%, depending on the amount of CNTs dispersed in an aqueous solution. Roller activation, which is a essential process to improve the field emission characteristics of CNT films, increased the UV-Vis transmittance up to 93~98%. This study presents SEM morphology of CNT emitters and their field emission properties according to the concentration of CNTs in an aqueous solutions. Since the ultra-thin CNT emitters prepared from the solutions show a high peak current density of field emission comparable to that of the paste-base CNT emitters and do not contain outgassing sources such as organic binders, they are considered to be very promising for small-size-but-high-end applications including X-ray sources and microwave power amplifiers.

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Fabrication of field emitters using a filtration-taping-transfer method

  • Song, Ye-Nan;Shin, Dong-Hoon;Sun, Yuning;Shin, Ji-Hong;Lee, Cheol-Jin
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.466-466
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    • 2011
  • There have been several methods to fabricate carbon nanotube (CNT) emitters, which include as-grown, spraying, screen-printing, electrophoresis and bonding methods. Unfortunately, these techniques generally suffer from two main problems. One is a weak mechanical adhesion between CNTs and the cathode. The as-grown, spraying and electrophoresis methods show a weak mechanical adhesion between CNTs and the cathodes, which induces CNT emitters pulled out under a high electric field. The other is a severe degradation of the CNT tip due to organic binders used in the fabrication process. The screen-printing method which is widely used to fabricate CNT emitters generally shows a critical degradation of CNT emitters caused by the organic binder. Such kinds of problems induce a short lifetime of the CNT field emitters which may limit their practical applications. Therefore, a robust CNT emitter which has the strong mechanical adhesion and no degradation is still a great challenge. Here, we introduce a simple and effective technique for fabrication of CNT field emitter, namely filtration-taping-transfer method. The CNT emitters fabricated by the filtration-taping-transfer method show the low turn-on electric fields, the high emission current, good uniformity and good stability. The enhanced emission performance of the CNT emitters is mainly attributed to high emission sites on the emitter area, and to good ohmic contact and strong mechanical adhesion between the emitters and cathodes. The CNT emitters using a simple and effective fabrication method can be applied for various field emission applications such as field emission displays, lamps, e-beam sources, and x-ray sources. The detail fabrication process will be covered at the poster.

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유리기판 위에 성장된 카본나노튜브를 이용한 고휘도 램프 특성 (Development of flat type back-lamp using carbon nano tubes grown on glass substrate)

  • 이양두;이덕중;박정훈;유재은;이윤희;장진;주병권
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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    • pp.89-92
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    • 2002
  • Carbon nano tubes(CNTs) have been reported as field emission source because has a sharp tip, a high aspect tip, high chemical stability, high mechanical strength and low work function properties. In this study, we fabricated successfully the back-lamp of the I-inch flat type using CNTs, which was grown directly on cathode substrate of sodalime glass at low temperature. The brightness of CNT back-lamp is measured to $14 Kcd/m^{2}$ at $2000V_{dc}$ in spacing of $500{\mu}m$. And, the emission properties of packaged CNT back-lamp was analyzed as function of applying voltage and times.

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선박평형수 처리를 위한 전기화학 반응에서 음극의 영향 (Effect of Cathode in Electrochemical Reaction for Treating Ballast Water)

  • 김동석;박혜진;윤종문;박용석;박영식
    • 한국환경과학회지
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    • 제23권6호
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    • pp.1175-1182
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    • 2014
  • In this study, we examined the effect of cathode from electrolysis reactor for treating ballast water. We are going to select a suitable cathode for seawater electrolysis after considering the effect on the generation of the oxidant of cathode and the electrode deposition materials adhering to the surface of cathode. Anode is Ru-Ti-Pd electrode and cathode are Ti, Pt, JP520 (Ni-Pt-Ce) electrodes. Using the cathode of the three types, experiments were conducted to examine the effects of TRO (total residual oxidants) generation concentration and RNO (N, N-Dimethyl-4-nitrosoaniline, indicator of the generation of OH radical) degradation concentration (in 1, 35 psu), ohmic drop, FESEM(field emission scanning electron microscope) observation of cathode surface and EDX (energy dispersive X-ray spectroscopy) measurements of attached fouling material. The results showed that TRO generation concentration and RNO degradation concentration in according to each type of cathode are not different. The attached fouling materials were observed on the surface of Ti and the JP520 electrode by the observation of SEM after electrolysis for two hours, but it was not observed on the surface of Pt electrode. When considering the surface ohmic drop of cathode and the attached fouling materials, Pt electrode was judged as the excellent cathode.

아르곤 이온에 의해 표면처리된 CNT 에미터의 전계방출 특성 (Field Emission Characteristics of Surface-treated CNT Emitter by Ar Ion Bombardment)

  • 권상직
    • 전자공학회논문지 IE
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    • 제44권2호
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    • pp.26-31
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    • 2007
  • 카본나노튜브 전계 방출 어레이(carbon nanotube field emission array, CNT FEA)를 유리기판 상에 형성시키기 위하여 CNT 페이스트를 스크린 프린팅 후 표면처리를 수행하였다. 본 실험에서는 효과적인 표면처리 방법으로서 이온 빔을 조사(expose)시키는 방법을 연구하였다. 먼저, 유리 기판상에 감광성 CNT 페이스트를 스크린 프린팅하고 UV 후면노광 및 현상공정에 의해 선택적으로 CNT 페이스트를 남겼다. 다시 고온에서 소성후 CNT들은 바인더 성분들에 의해 문히게 된다. 본 실험에서는 소성된 CNT 페이스트의 표면상에 Ar 이온빔을 가속시켜 페이스트의 바인더(binder)를 선택적으로 제거함으로써 전계방출 특성을 향상시킬 수 있었다. 표면처리를 위한 이온 빔 가속시 이온빔의 가속에너지에 따라 특성이 크게 변화되었는데, 본 연구에서는 100 V의 낮은 가속 전압에서 가장 높은 전계방출 특성을 나타내었으며 가속 전압이 너무 높으면 바인더 성분 외에도 CNT 자체가 제거됨으로써 오히려 특정이 저하됨을 알 수 있었다.

반전층에서의 애벌런치 현상을 이용한 냉음극 (Cold Cathode using Avalanche Phenomenon at the Inversion Layer)

  • 이정용
    • 한국진공학회지
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    • 제16권6호
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    • pp.414-423
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    • 2007
  • FED(Field Emission Display)는 특히 소형, 고품질 평면화면분야에서 종래의 기술들과 뚜렷이 구별되는 이점을 가지고 있다. FED를 실리콘 웨이퍼에 System-on-Chip(SoC)화하는 가능성을 검토하기 위해, 우리는 p-n 접합을 평면 디스플레이의 전자선원(electron beam source)으로 사용할 수 있는지를 실험하였다. Cantilever(외팔보)형 게이트로부터의 전계로 반전층을 형성하여 p-n 접합을 형성하는 새로운 구조를 제조하였다. 약 1 ${\mu}m$ 정도의 높이에 있는 cantilever형 게이트에 220V이상의 전압을 가했을 때 반전층(inversion layer)이 형성되었고, 애벌런치 항복이성공적으로 이루어졌다. 극히 얕은 p-n 접합에서 애벌런치 항복 시 관측되는 전자방출 효과와 그 특성이 비교되었고 실험결과와 향후 연구방향이 논의 되었다.

Synthesis and Properties of Carbon Nanotube Paste with Different Inorganic Binders for Field Emission Display

  • Park, Jae-Hong;Moon, Jin-San;Nam, Joong-Woo;Park, Jong-Hwan;Berdinsky, A.S.;Yoo, Ji-Beom;Lee, C.G.;Park, Chong-Yun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.468-470
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    • 2004
  • CNT pastes with different inorganic binder such as glass frit and spin on glass (SOG) were synthesized by using multi-walled nanotube (MWNT) grown by CVD. The uniformity of cathode layer after firing was enhanced and the emission current density at an applied field of 7.95V/${\mu}m$ increased from 133${\mu}A$/$cm^2$ to 265${\mu}A$/$cm^2$ when inorganic binder changed from glass frit to SOG. The emission properties of CNT pastes with SOG were stable and uniform although firing was carried out at relatively high temperature of 450$^{\circ}C$ under air. It is concluded that SOG is more suitable inorganic binder than glass frit for field emission application.

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