• 제목/요약/키워드: Emitters

검색결과 307건 처리시간 0.035초

Electron Beam Coherency Determined from Interferograms of Carbon Nanotubes

  • Cho, B.;Oshima, C.
    • Bulletin of the Korean Chemical Society
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    • 제34권3호
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    • pp.892-898
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    • 2013
  • A field emission projection microscope was constructed to investigate the atomic and chemical-bonding structure of molecules using electron in-line holography. Fringes of carbon nanotube images were found to be interferograms equivalent to those created by the electron biprism in conventional electron microscopy. By exploiting carbon nanotubes as the filament of the electron biprism, we measured the transverse coherence length of the electron beam from tungsten field emitters. The measurements revealed that a partially coherent electron-beam was emitted from a finite area.

Fabrication and Driving of Active-Matrix Field Emission Display

  • Song, Yoon-Ho;Jeong, Jin-Woo;Kim, Dae-Jun;Kang, Jun-Tae;Cho, Kyoung-Ik
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.483-485
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    • 2007
  • The active-matrix field emission display (AMFED) was fabricated by integrating carbon nanotube emitters on a-Si thin-film transistors. Also, the tapered macro-gate was adopted for high immunity to a high anode voltage and strong electron beam focusing. The fabricated AMFED was successfully driven with a low voltage of below 15 V.

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전자현미경의 전자원 (Electron sources for electron microsocpes)

  • 조복래
    • 진공이야기
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    • 제2권2호
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    • pp.24-28
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    • 2015
  • The brightness of an electron source, along with the aberrations of an objective lens, determines the image resolution and beam current on samples, which are two important parameters for evaluating the performance of an electron microscope. Here we introduce thermal electron source, Schottky emitter and cold field electron emitter. Thermal electron source is the cheapest and stable electron source but it has the lowest brightness. Schottky emitter is 10000 times brighter than tungsten thermal electron source, but requires ultrahigh vacuum operating condition. Cold field electron emitter is 10 times brighter than Schottky emitters, but it is rather unstable and its operation requires most stringent vacuum condition, hindering its widespread use.

장수명 플라즈마 건의 개발 (Development of a plasma gun for long lifetime)

  • 최영욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 Techno-Fair 및 추계학술대회 논문집 전기물성,응용부문
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    • pp.192-193
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    • 2007
  • A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride ($LaB_6$) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the $LaB_6$, which is also useful for optimal fixing of the $LaB_6$. The hollow cathode is capable of producing 30 kW (100 V, 300 A) of power continuously.

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The Efficient Production on single- and Multi- Wall Carbon Nanotubes

  • Shinohara, H.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.207-207
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    • 2000
  • Multi- and single-wall carbon nanotubes are promising new carbon materials in nano-electronics, field-emitters, CRT-displays, hydrogen storage materials, biomedical tracers and so forth. The present talk will deal with a high-yield synthesis on quasi-aligned multi-wall carbon nanotubes via a chemical vapor deposition technique. I will also talk about a possible growth mechanism on single-wall carbon nanotubes based on newly obtained experimental results.

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Triode-Type Field Emission Displays with Carbon Nanotube Emitters

  • You, J.H.;Lee, C.G.;Jung, J.E.;Jin, Y.W.;Jo, S.H.;Nam, J.W.;Kim, J.W.;Lee, J.S.;Jang, J.E.;Park, N.S.;Cha, J.C.;Chi, E.J.;Lee, S.J.;Cha, S.N.;Park, Y.J.;Ko, T.Y.;Choi, J.H.;Lee, S.J.;Hwang, S.Y.;Chung, D.S.;Park, S.H.;Kim, J.M.
    • Journal of Information Display
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    • 제2권3호
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    • pp.48-53
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    • 2001
  • Carbon nanotube emitters, prepared by screen printing, have demonstrated a great potential towards low-cost, largearea field emission displays. Carbon nanotube paste, essential to the screen printing technology, was formulated to exhibit low threshold electric fields as well as an emission uniformity over a large area. Two different types of triode structures, normal gate and undergate, have been investigated, leading us to the optimal structure designing. These carbon nanotube FEDs demonstrated color separation and high brightness over 300 $cd/m^2$ at a video-speed operation of moving images. Our recent developments are discussed in details.

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탄소 나노튜브 위에 붕소 및 탄소 질화 박막이 코팅된 이종접합 구조 미세팁의 전자방출 특성 (Electron Emission Properties of Hetero-Junction Structured Carbon Nanotube Microtips Coated With BN And CN Thin Films)

  • 노영록;김종필;박진석
    • 전기학회논문지
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    • 제59권4호
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    • pp.743-748
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    • 2010
  • Boron nitride (BN) and carbon nitride (CN) films, which have relatively low work functions and commonly exhibit negative electron affinity behaviors, were coated on carbon nanotubes (CNTs) by magnetron sputtering. The CNTs were directly grown on metal-tip (tungsten, approximately 500nm in diameter at the summit part) substrates by inductively coupled plasma-chemical vapor deposition (ICP-CVD). The variations in the morphology and microstructure of CNTs due to coating of the BN and CN films were analyzed by field-emission scanning electron microscopy (FE-SEM). The energy dispersive x-ray (EDX) spectroscopy and Raman spectroscopy were used to identify the existence of the coated layers (CN and BN) on CNTs. The electron-emission properties of the BN-coated and CN-coated CNT-emitters were characterized using a high-vacuum field emission measurement system, in terms of their maximum emission currents ($I_{max}$) at 1kV and turn-on voltage ($V_{on}$) for approaching $1{\mu}A$. The results showed that the $I_{max}$ current was significantly increased and the $V_{on}$ voltage were remarkably reduced by the coating of CN or BN films. The measured values of $I_{max}-V_{on}$ were as follows; $176{\mu}A$-500V for the 5nm CN-coated emitter and $289{\mu}A$-540V for the 2nm BN-coated emitter, respectively, while the $I_{max}-V_{on}$ of the as-grown (i.e., uncoated) emitter was $134{\mu}A$-620V. In addition, the CNT emitters coated with thin CN or BN films also showed much better long-term (up to 25h) stability behaviors in electron emission, as compared with the conventional CNT emitter.