• Title/Summary/Keyword: Field emission cathode

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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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    • 2006.08a
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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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    • 2002.08a
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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
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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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
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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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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Development of flat type back-lamp using carbon nano tubes grown on glass substrate (유리기판 위에 성장된 카본나노튜브를 이용한 고휘도 램프 특성)

  • Lee, Yang-Doo;Lee, Duck-Jung;Park, Jeung-Hoon;Yoo, Jae-Eun;Lee, Yun-Hi;Jang, Jin;Ju, Byeong-Kwon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.04b
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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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Effect of Cathode in Electrochemical Reaction for Treating Ballast Water (선박평형수 처리를 위한 전기화학 반응에서 음극의 영향)

  • Kim, Dong Seog;Park, Hye Jin;Yoon, Jong Mun;Park, Yong Seok;Park, Young Seek
    • Journal of Environmental Science International
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    • v.23 no.6
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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.

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

  • Kwon, Sang-Jik
    • 전자공학회논문지 IE
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    • v.44 no.2
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    • pp.26-31
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    • 2007
  • A surface treatment was performed after the screen printing of a carbon nanotube paste for obtaining the carbon nanotube field emission array(CNT FEA) on the soda-lime glass substrate. In this experiment, Ar ion bombardment was applied as an effective surface treatment method. After making a cathode electrode on the glass substrate, photo sensitive CNT paste was screen-printed, and then back-side was exposure by uv light. Then, the exposed CNT paste was selectively remained by development. After post-baking, the remained CNT paste was bombarded by accelerated Ar ions for removing some binders and exposing only CNTs. As results, the field emission characteristics were strongly depended on the accelerating energy. At 100 eV, the emission was highest and as the acceleration energy increases more then 100 eV, the emission decreased. This was due to the removal of CNT itself as well as binders.

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

  • Lee, Jung-Yong
    • Journal of the Korean Vacuum Society
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    • v.16 no.6
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    • pp.414-423
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    • 2007
  • Field Emission Display(FED) has significant advantages over existing display technologies, particularly in the area of small and high quality display. In order to test the feasibility of fabricating the System-on-Chip(SOC) with FED, we conducted the experiment to use the p-n junction as an electron beam source for the flat panel display. A novel structure was constructed to form p-n junctions by generating inversion layer with the electric field from the cantilever style gate. When we applied more than 220V at the cantilever style gate which has a height of $1{\mu}m$, avalanche breakdown onset was successfully achieved. The characteristics was compared with the electron emission from the ultra shallow junction in the avalanche region. The experiment result and the future direction were discussed.

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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    • 2004.08a
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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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