• Title/Summary/Keyword: Emitters

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The dual emitter structure for field emission light source (전계방출광원용 듀얼 에미터 특성 연구)

  • Kim, Kwang-Bok;Lee, Sun-Hee;Park, Ho-Seop;Yang, Dong-Wook;Kim, Dae-Jun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2008.05a
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    • pp.151-154
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    • 2008
  • The field emission lamps have the advantages to their cold cathode-characteristic and the eco-friendly, We realized that the dual emitter system showed very simple structure which gate and cathode electrodes are formed on the same glass surface. In this paper, we reported the properties of dual emitters depended on variation of gate width and spacing for optimum panel structure. In combination of dual emitter structure and bi-polar driving, electron beam spreads more than normal gate structure or diode structure, and emission uniformity increased in dual emitter structure at 5"-diagonal.

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A Fairness Based T-MAC Protocol in Wireless Sensor Network (무선 센서 네트워크에서 공평성을 고려한 T-MAC 프로토콜)

  • Nam, Jaehyun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.329-331
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    • 2013
  • IEEE 802.11 has become the main technology in wireless network. However, in terms of fairness, arise in its use in ad hoc networks. Two independent emitters nodes can easily monopolize the medium, preventing other nodes to send packets. This paper proposes the modified (m,k)-firm scheme which is based on T-MAC to improve fairness. Also, the proposed scheme uses different TA period according to the number of collision in the node. The simulation result shows that the proposed scheme helps improve the fairness of the DCF.

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Vacuum Dependency of Si, Co Slicide and Mo Silicide FEAs

  • Lee, Jong-Duk;Shim, Byung-Chang;Park, Byung-Gook;Uh, Hyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.685-688
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    • 2002
  • In this paper, it is reported that the anode current changes at the constantly applied gate voltages and the current-voltage (I-V) characteristics of Si, Co silicide and Mo silicide field emitter arrays (FEAs) depending on vacuum level from a $10^{-9}$ torr to a $10^{-6}$ torr. The mechanism of the robustness of anode current degradation of Mo silicide FEAs under poor vacuum conditions can be explained by the model of tolerance for the oxygen adsorption and oxidation at the silicide surface. Also, we present the changes of emitting area and work function of the emitters according to vacuum level.

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Thermal Effects of Single Silicon Tip Emitters with Various Tip Radii

  • Lee, Jong-Duk;Oh, Chang-Woo;Park, Jae-Woo;Park, Byung-Gook
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.681-684
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    • 2002
  • To investigate thermal effects of silicon field emitter, we fabricated and characterized single silicon tips with various tip radii, which generate different joule heating. Through I-V and stability tests, the changes of emission characteristics and tip structures due to different tip heating were observed and discussed. From the results, we confirmed that the changes of emission characteristics due to thermal effects in silicon emitter could occur at relatively small emission currents and concluded that the thermal effects should be also considered under normal operation condition above 1 ${\mu}A$.

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SIMULATION OF THIN-FILM FIELD EMITTER TRIODE

  • Park, Kyung-Ho;Lee, Soon-Il;Koh, Ken-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.651-654
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    • 2002
  • We carried out 2-dimensional numerical calculations of electrostatic potential for triode field emitters with planar cathodes using the finite element method. As it turned out, the conventional triode structure with a planar cathode suffered from large gate current and wide spreading of emitted electrons. To circumvent these shortcomings, we proposed a new triode structure. By simply inserting a conducting layer of proper thickness on top of the cathode layer, we were able to modify the electric field distribution on the cathode surface so that low gate current and electron-focusing effect were achieved, simultaneously.

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Development of Active Matrix Cathodes Composed of a-Si:H TFTs and Gated Molybdenum Field Emitter Arrays

  • Chung, Choong-Heui;Song, Yoon-Ho;Hwang, Chi-Sun;Ahn, Seong-Deok;Kim, Bong-Chul;Cho, Young-Rae;Lee, Jin-Ho;Cho, Kyoung-Ik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.1020-1023
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    • 2002
  • We successfully developed a-Si TFT controlled active matrix cathode (AMC) with gated Mo emitters. Also, we could remove emitter failures of the AMC through a novel surface treatment of Mo-tips, which indicates reduction of $MoO_3$ or chemical wet etching of $MoO_3$ by surface treatment. Transient behaviors of the AMC are strongly dependent on not only DC characteristics of device but also the device structure. Brightness and gray scale were well realized by low-voltage scan and data signals addressed to a-Si TFTs.

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Field Emission from Single-Walled Carbon Nanotubes Aligned on a Gold Plate using Self-Assembly Monolayer

  • Lee, Ok-Joo;Jeong, Soo-Hwan;Lee, Kun-Hong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.305-308
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    • 2002
  • Field emission from single-walled carbon nanotubes (SWNTs) aligned on a patterned gold surface is reported. The SWNTs emitters were prepared at room temperature by a self-assembly monolayer technique. SWNTs were cut into sub-micron length by sonication in an acidic solution. Cut SWNTs were attached on the gold surface by the reaction between the thiol groups and the gold surface. The field emission measurement showed that the turn-on field was 4.8 $V/{\mu}m$ at the emission current density of 10 ${\mu}A/cm^2$. The current density was 0.5 $mA/cm^2$ at 6.6 $V/{\mu}m$. This approach provides a novel route for fabricating CNT-based field emission displays.

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A simulation study on vertical focusing in micro-tip FED

  • Lee, Chun-Gyioo;Jo, Sung-Ho;Ko, Tae-Young;Moon, Soo-Young;Yunsoo Choe
    • Journal of Korean Vacuum Science & Technology
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    • v.3 no.1
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    • pp.30-32
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    • 1999
  • Electron beam trajectory simulation results on the high voltage FED with cone-type field emitters predict that the cross-talk phenomena would be seen due to the divergence of the electron beam. In this study, computer simulations with design of experiment technique and the SNU-FEAT program were carried out for five input parameters of the aperture focusing structure. The results tell that the focusing voltage is a dominant factor. And, the beam divergence index could be reduced to 10.7$\mu\textrm{m}$ with the aperture focusing structure, however, the operating voltage of the field emitter is predicted to increase by 40% maximum.

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ERRATUM : 'LYMANα EMITTERS BEYOND REDSHIFT 5: THE DAWN OF GALAXY FORMATION' (JKAS, 36, 123, [2003])

  • Taniguchi, Yoshiaki;Shioya, Yasuhiro;Ajiki, Masaru;Fujita, Shinobu S.;Nagao, Tohru;Murayama, Takashi
    • Journal of The Korean Astronomical Society
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    • v.36 no.4
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    • pp.283-283
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    • 2003
  • The first sentence in the second paragraph of INTRODUCTION, 'The first discovery of a galaxy beyond z=5 was reported by Weymann et al. (1998); HDF 4-470.3 at z=5.60.' should be read as 'The first discovery of a galaxy beyond z=5 was reported by Dey et al. (1998); 0140+326 RD1 at z=5.34'. The authors sincerely regret this error.

Effects of Selective Growth on Electron-emission Properties of Conical-type Carbon Nanotube Field-emitters (원추형 기판 위에 탄소 나노튜브의 선택적 성장이 전계방출 특성에 미치는 영향)

  • Kim, Bu-Jong;Noh, Young-Rok;Park, Jin-Seok
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.1
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    • pp.61-65
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    • 2012
  • In this study, for use of carbon nanotubes (CNTs) as a cold cathode of x-ray tubes, we examine the effects of selective growth of CNTs on their field emission properties and long-term stability. The selective growth of CNTs was performed by selectively etching the catalyst layer which was used for CNTs' nucleation. CNTs were grown on conical-type tungsten substrates using an inductively-coupled plasma chemical vapor deposition system. For all the grown CNTs, their morphologies and microstructures were analyzed by field-emission scanning electron microscope and Raman spectroscopy. The electron-emission properties of CNTs and the long-term stability of emission currents were measured and characterized according to the CNTs' growth position on the substrate.