• 제목/요약/키워드: thermal emitter

검색결과 80건 처리시간 0.025초

정공 전달물질 및 적색발광 물질이 곁사슬에 포함된 비공액 고분자의 합성과 특성 분석 (Synthesis and Characterization of Non-Conjugated Polymers with Hole-Conductor and Red-Emitter in Side-Chain)

  • 심나영;이후성
    • 폴리머
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    • 제29권5호
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    • pp.486-492
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    • 2005
  • 적색을 낼 수 있는 물질을 만들기 위해 비공액 주사슬로 되어 있는 고분자의 곁사슬에 스티렌 분자가 연결되어 있는 트리페닐아민, 반응성 있는 작용기를 가진 아미노벤즈알데히드 그룹, 및 PM(4-(dicyanomethylene)-2-(tertbutyl)4H-pyran) 그룹을 도입하였다. 이 고분자의 전자 흡수 스펙트럼은 용액과 필름 상태에서 비슷하였다. 모든 고분자는 전기화학적으로 활성을 보였으며, 전기 발광 소자를 작동하였을 때 700nm 근처에서 적색을 보였다. $ITO/PPV/P5-PM/BCP/Alq_3/Al$으로 구성된 소자는 $50mA/cm^2$의 낮은 전류 밀도에서 $120cd/m^2$의 밝기를 보였으며, 외부 양자 효율은 $0.67\%$를 나타내었다. 발광 고분자 층에서의 균형있는 전하의 재결합을 유도하여 소자의 발광 효율을 높일 수 있었다. 이중 기능성(bifunctionalized)을 도입함으로써 적색 발광을 내면서 효율이 높은 발광 고분자를 개발하였다.

후면 에미터 구조의 n-type 결정질 실리콘 태양전지 제작 및 최적화 연구

  • 탁성주;김영도;박성은;김동환
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 추계학술발표대회
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    • pp.12.1-12.1
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    • 2011
  • 최근 p-type 결정질 실리콘 태양전지의 광열화현상(light induced degradation)에 대한 관심이 높아지면서, 이를 해결하기 위한 많은 연구들이 수행되고 있다. 본 연구에서는 LID 현상을 원천적으로 제거 할수 있는 n-type 기판을 이용하여, 상업적으로 양산화 가능한 공정을 도입하고, 시뮬레이션을 통하여 고효율화 방안을 제시하고자 한다. 이를 위해 일반적인 p-type 결정질 실리콘 태양전지 제작 공정을 사용하여 알루미늄이 도핑된 후면 에미터 구조의 n-type 결정질 실리콘 태양전지를 제작하였으며, PC1D 시뮬레이션을 통해서 n+/n/p+구조의 n-type 결정질 실리콘 태양전지의 에너지 변환 효율 향상을 위한 방안을 제시하였다.

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질량 분석기에 응용할 수 있는 탄소나노튜브를 이용한 전자방출원 제작 (Fabrication of CNT(Carbon Nanotubes) Emitter for Mass Spectrometer)

  • 정대중;윤현중;정광우;양상식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.293-296
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    • 2003
  • We report on the fabrication and field emission of carbon nanotube field emitters for mass spectrometer. Due to its high aspect ratio and mechanical strength, we use vertically aligned multi-wall carbon nanotubes prepared by thermal chemical vapour deposition as cathodes, Electrons emitted from a CNT are to ionize some sample molecules. We have successfully attained patterned carbon nanotubes grown on two-dimensional 0.7 mm by 0.7 mm Ni square blocks on Si. The emission characteristics show that the field emission initiates at 200 V.

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Characteristics of Electron Beam Extraction in Large Area Electron Beam Generator

  • Woo, Sung-Hun;Lee, Hong-Sik
    • KIEE International Transactions on Electrophysics and Applications
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    • 제4C권1호
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    • pp.10-14
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    • 2004
  • A large area electron beam generator has been developed for industrial applications, for example, waste water cleaning, flue gas treatment, and food pasteurization. The operational principle is based on the emission of secondary electrons from the cathode when ions in the plasma contact the cathode, which are accelerated toward the exit window by the gradient of the electric potential. Conventional electron beam generators require an electron beam scanning mechanism because a small area thermal electron emitter is used. The electron beam of the large area electron beam generator does not need to be scanned over target material because the beam area is considerable. We have fabricated a large area electron beam generator with peak energy of 200keV, and a beam diameter of 200mm. The electron beam current has been investigated as a function of accelerating voltage and distance from the extracting window while its radial distribution in front of the extracting window has been also measured.

1100 ${\AA}$의 베이스 폭을 갖는 다결정 실리콘 자기정렬 트랜지스터 특성 연구 (A Study on the Characteristics of PSA Bipolar Transistor with Thin Base Width of 1100 ${\AA}$)

  • 구용서;안철
    • 전자공학회논문지A
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    • 제30A권10호
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    • pp.41-50
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    • 1993
  • This paper describes the fabrication process and electrical characteristics of PSA (Polysilicon Self-Align) bipolar transistors with a thin base width of 1100.angs.. To realize this shallow junction depth, one-step rapid thermal annealing(RTA) technology has been applied instead of conventional furnace annealing process. It has been shown that the series resistances and parasitic capacitances are significantly reduced in the device with emitter area of 1${\times}4{\mu}m^{2}$. The switching speed of 2.4ns/gate was obtained by measuring the minimum propagation delay time in the I$^{2}$L ring oscillator with 31 stages.

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Fabrication and Characteristics of CNT-FEAs with Under-gate Structure

  • Noh, Hyung-Wook;Jun, Pil-Goo;Ko, Sung-Woo;Kwak, Byung-Hwak;Park, Sang-Sik;Lee, Jong-Duk;Uh, Hyung-Soo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1470-1473
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    • 2005
  • We proposed new triode-type Field Emitter Arays using Carbon NanoTubes(CNT-FEAs) as electron emission sources at low electric fields. The CNTs were selectively grown on the patterned catalyst layer by Plasma-Enhanced Chemical Vapor Deposition (PECVD). In this structure, gate electrodes are located underneath the cathode electrodes and extracted gate is surrounded by CNT emitters. Furthermore, in order to control density of CNTs, we investigated effect of using rapid thermal annealing (RTA).

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Impact of Passivation and Reliability for Base-exposed InGaP/GaAs HBTs

  • Park, Jae-Woo
    • Transactions on Electrical and Electronic Materials
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    • 제8권3호
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    • pp.115-120
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    • 2007
  • Reliability between passivated and unpassivated process with the base-exposed InGaP/GaAs HBTs was studied. A passivation of HBT was attempted by $SiO_2$ thin film deposition at $300^{\circ}C$ by means of PECVD. Base-exposed InGaP/GaAs HBTs before and after passivation were investigated and compared in terms of DC and RF performance. Over a total period of 30 days, passivated HBTs show only 2% degradation of DC current gain for the high current density of $40KA/cm^2$. The measured thermal resistance of $2{\times}30{\mu}m^2$ single emitter InGaP/GaAs HBT passivated with PECVD $SiO_2$ devices can be extracted and was founded to be 1430 K/W. The estimated MTTF was $2{\times}10^7hr\;at\;T_j=125^{\circ}C$ with an activation energy $(E_a)$ of 1.37 eV.

저전력 CMOS 기준전류 발생회로 (A Low-Power CMOS Current Reference Circuit)

  • 김유환;권덕기;이종렬;유종근
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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    • pp.89-92
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    • 2001
  • In this paper, a simple low-power CMOS current reference circuit is proposed. The reference circuit includes parasitic pnp BJTs and resistors. Temperature compensation is made by adding a current component proportional to a thermal voltage to a current component proportional to a base-to-emitter voltage. The designed circuit has been simulated using a 0.25${\mu}{\textrm}{m}$ n-well CMOS process parameters. The simulation results show that the reference current is 34.96$mutextrm{A}$$\pm$0.04$mutextrm{A}$ in the temperature range of -2$0^{\circ}C$ to 12$0^{\circ}C$ The reference current varies less than 0.6% when the power supply voltage changes from 2.5V to 3.5V For $V_{DD=5V}$ and T=3$0^{\circ}C$ the power consumption is 520㎼ during normal operation but reduces to 0.l㎻ during power-down mode.

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전계방출광원용 카본나노파이버 에미터 연구 (Study on Carbon Nano Fiber Emitter for Field Emission Lamp)

  • 김광복;이선희;유승호;김대준;김용원
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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    • pp.21-24
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    • 2008
  • Properties of carbon nano fiber (CNF) as field emitters were described. Carbon nano fiber (CNF) of herringbone was prepared by thermal chemical vapor deposition(CVD). Field emitters mixed with organic binders, conductive materials and were prepared by screen-printing process. In order to increase field emissions, the surface treatment of rubbing & peel-off was applied to the printed CNF emitters on cathode electrode. The measurements of field emission properties were carried out by using a diode structure inline vacuum chamber. CNF of herringbone type showed good emission properties that a turn on field was as low as 2.1 $V/{\mu}m$ and current density was as large as 0.15 $mA/cm^2$ of 4.2 $V/{\mu}m$ with electric field. Through the results. we propose that CNFs are suitable for application of electron emitters in Field Emission Devices.

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Low-voltage cathodoluminescent Characteristics of ZnGa$_2$O$_4$ : Mn phosphors

  • 조성희;유재수;이종덕;이중환
    • 한국표면공학회지
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    • 제30권1호
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    • pp.57-62
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    • 1997
  • Green-emitting $ZnGa_2O_4$ : Mn phosphors were synthesized by a thermal method and their low-voltage cathodoluminescent characteristics were examined for the field emitter display (FED) application. Low efficiency of $ZnGa_2O_4$ : Mn phosphors could be ascribed to the low penetration depth of into phosphors, which might results in charge accumulation on the phosphors screen. For increasing cathodoluminescent of $ZnGa_2O_4$ : Mn under low voltage excitation, wide band-gap oxide materials were added to the $ZnGa_2O_4$: Mn powder. It is found that the luminance can be increased by 20%. Measurement of leakage current on the phosphor screen shows that the enhancement of low-voltage cathodoluminescent by additive materials is mainly due to the consumption of surface charges on the phosphor.

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