• 제목/요약/키워드: Ohmic

검색결과 614건 처리시간 0.025초

고농도의 Mg가 도핑된 GaN층을 이용한 GaN계 청자색 레이저다이오드의 동작 전압 감소 (Reduction of Operating Voltage of GaN-based Blue-violet Laser Diode by using Highly Mg Doped GaN Layer)

  • 곽준섭
    • 한국전기전자재료학회논문지
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    • 제17권7호
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    • pp.764-769
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    • 2004
  • In order to reduce operating voltage of the GaN based blue-violet laser diodes, the effect of highly Mg doped GaN layer, which was grown below ohmic contact metals, on contact resistivity as well as operating voltage has been investigated. The addition of the highly Mg doped GaN layer greatly reduced contact resistivity of Pd/Pt/Au ohmic contacts from $5.2 \times {10}^-2 \Omegaㆍ$\textrm{cm}^2$ to 7.5 \times {10}^-4 \Omegaㆍ$\textrm{cm}^2$$. In addition, it also decreased device voltage at 20 mA by more than 3 V. Temperature- dependent sheet resistivity of the highly Mg doped GaN layer suggested that the reduction of the contact resistivity could be attributed to predominant current flow at the interface between the Pd/Pt/Au contacts and p-GaN through a deep level defect band, rather than the valence band.

Effects of an Aluminum Contact on the Carrier Mobility and Threshold Voltage of Zinc Tin Oxide Transparent Thin Film Transistors

  • Ma, Tae-Young
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.609-614
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    • 2014
  • We fabricated amorphous zinc tin oxide (ZTO) transparent thin-film transistors (TTFTs). The effects of Al electrode on the mobility and threshold voltage of the ZTO TTFTs were investigated. It was found that the aluminum (Al)-ZTO contact decreased the mobility and increased the threshold voltage. Traps, originating from $AlO_x$, were assumed to be the cause of degradation. An indium tin oxide film was inserted between Al and ZTO as a buffer layer, forming an ohmic contact, which was revealed to improve the performance of ZTO TTFTs.

HYDROMAGNETIC ROTATING DISK FLOW OF A NON-NEWTONIAN FLUID WITH HEAT TRANSFER AND OHMIC HEATING

  • Attia, Hazem A.;Ewis, Karem M.;Abd Elmaksoud, Ibrahim H.;Awad-Allah, Nabil A.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • 제16권3호
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    • pp.169-180
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    • 2012
  • The steady hydromagnetic flow of an electrically conducting non-Newtonian fluid due to the rotation of an infinite disk is studied with heat transfer with the inclusion of the ion slip as well as Ohmic heating. The governing nonlinear momentum equations and energy equations are solved using the finite difference method. The numerical results indicate the important effect of the ion slip and the non-Newtonian fluid characteristics on the velocity and temperature distributions.

유기발광소자(OLED)의 전기전도메커니즘에 대한 고찰 (Study on the Electrical Conduction Mechanism of Organic Light-Emitting Diodes (OLEDs))

  • 이원재
    • 반도체디스플레이기술학회지
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    • 제17권4호
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    • pp.6-10
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    • 2018
  • Organic light emitting devices have attracted the attention of many people because of their high potential for self-emission and flexible display devices. However, due to limitations in device efficiency and lifetime, partial commercialization is underway. In this paper, we have investigated the electrical conduction mechanism of the organic light emitting device by the temperature and the thickness of the light emitting layer through the current - voltage characteristics with respect to the conduction mechanism directly affecting the efficiency and lifetime of the organic light emitting device. Through the study, it was found that the conduction in the low electric field region is caused by the movement of the heat excited charge in the ohmic region and the tunneling of the electric charge due to the high electric field in the high electric field region.

탄소나노튜브 페이스트 접합에 의한 탄소계 복합저항체의 전기적 특성 (Electrical Properties of Carbon-Based Hybrid Resistor Bonded with Carbon Nanotube Paste)

  • 이선우;김은민
    • 한국전기전자재료학회논문지
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    • 제36권5호
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    • pp.482-487
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    • 2023
  • A carbon-based hybrid resistor was fabricated using carbon nanotube (CNT) paste as an adhesive layer to establish electrically continuous ohmic contacts between CNT sheets and different CNT sheet or copper based metal alloy plates, and its electrical properties were evaluated. CNT sheets were fabricated using vacuum filtration with a CNT solution dispersed in isopropyl alcohol (IPA) solvent. The electrical characteristics of these carbon-based hybrid resistors were investigated. The CNT paste fulfilled the requirements for forming ohmic contacts between CNT sheets and metal alloy plates, which was attributed to the lowest work function difference and excellent wettability at the interface.

열처리에 따른 p-GaN의 오믹접촉 특성에 관한 연구 (Study on characteristics of p-GaN ohmic contacts by rapid thermal annealing)

  • 김두수;이세준;성규석;강윤묵;차정호;김남화;정웅;조훈영;강태원;김득영;이연환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
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    • pp.310-313
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    • 2000
  • In this study, the Au/Ni and Au/Ni/Si/Ni layers prepared by electron beam evaporation were used to form ohmic contacts on p-type GaN. Before rapid thermal annealing, the current-voltage(I-V) characteristic of Au/Ni and Au/Ni/Si/Ni contact on p-type GaN film shows non-ohmic behavior. A Specific contact resistance as 3.4$\times$10$^{-4}$ Ω-$\textrm{cm}^2$ was obtained after 45$0^{\circ}C$-RTA. The Schottky barrier height reduction may be attributed to the presence of Ga-Ni and Ga-Au compounds, such as Ga$_4$Ni$_3$, Ga$_4$Ni$_3$, and GaAu$_2$ at the metal - semiconductor interface. The mixing behaviors of both Ni and Au have been studied by using X-ray photoelectron spectroscopy. In addition, X-ray diffraction measurements indicate that the Ni$_3$N, NiGa$_4$, Ni$_2$Si, and Ni$_3$Si$_2$ Compounds were formed at the metal-semiconductor interface.

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