• Title/Summary/Keyword: carrier transport

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Efficient White Organic Light-Emitting Diodes (WOLEDs) with Device Structure Modification

  • Kim, Jun-Ho;Seo, Ji-Hoon;Seo, Ji-Hyun;Hyung, Gun-Woo;Lee, Kum-Hee;Yoon, Seoung-Soo;Kim, Young-Kwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1403-1406
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    • 2007
  • An effective WOLED structure was demonstrated which improved a luminous efficiency and white color chromaticity independent on applied bias by employing effective carrier transporting layer, without any alteration of emissive materials. The modified WOLEDs exhibited 2 times higher luminous efficiency than the control device and showed balanced white emission during an operation.

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Organic Bistable Switching Memory Devices with MeH-PPV and Graphene Oxide Composite

  • Senthilkumar, V.;Kim, Yong Soo
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.5
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    • pp.290-292
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    • 2015
  • We have reported about bipolar resistive switching effect on Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]:Graphene oxide composite films, which are sandwiched between aluminum and indium tin oxide electrodes. In this case, I-V sweep curve showed a hysteretic behavior, which varied according to the polarity of the applied voltage bias. The device exhibited excellent switching characteristics, with the ON/OFF ratio being approximately two orders in magnitude. The device had good endurance (105 cycles without degradation) and long retention time (5 × 103 s) at room temperature. The bistable switching behavior varied according to the trapping and de-trapping of charges on GO sites; the carrier transport was described using the space-charge-limited current (SCLC) model.

The Structure, Surface Morphology and Electrical Properties of ZrO2 Metal-insulator-metal Capacitors (ZrO2 MIM 캐패시터의 구조, 표면 형상 및 전기적 특성)

  • Kim Dae Kyu;Lee Chongmu
    • Korean Journal of Materials Research
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    • v.15 no.2
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    • pp.139-142
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    • 2005
  • [ $ZrO_2$ ] gate dielectric thin films were deposited by radio frequency (rf)-magnetron sputtering and its structure, surface morphology and electrical peoperties were studied. As the oxygen flow rate increases, the surface becomes smoother. The experimental results indicate that a high temperature annealing is desirable since it improves the electrical properties of the $ZrO_2$ gate dielectric thin films by decreasing the number of interfacial traps at the $ZrO_2/Si$ interface. The carrier transport mechanism is dominated by the thermionic emission.

산소흡탈착능을 가지는 산소부화막의 개발

  • ;;荒木 孝二
    • Proceedings of the Membrane Society of Korea Conference
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    • 1997.10a
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    • pp.21-24
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    • 1997
  • 1.서론 : 산소선택성이 좋은 투과막은 산소부화에 의한 연소효율의 향상, 간이 산소발생장치에의 응용 등 여러가지의 용도가 예상된다. 이를 위한 준비단계로 막소재 및 막형상에 대한 검토가 \ulcorner발하게 진행되고 있다. 그 중에서 높은 산소선택성을 발현하는 방법이 주목되어지고 있는데 이는 가역적 산소흡탈착능을 갖는 carrier분자를 이용한 촉지운송계(facilitated transport system)를 구축하는 방법이 있다. 본 연구에서는 [Co(salen)]과 같은 $N_2O_2$형 평면정방착제(Square planar complex)이며, salen의 shift염기부분을 bipyridine cycle, phenoxide부분을 해리한 amide로 골격변환한 구조를 갖고 있는 6,6'-bis(benzoylamino)-2,2'-bipyridine(babpH$_2$)의 covalt착체([Co(babp)]를 배위결합에 의해 고분자막중에 고정하고, 산소흡탈착능, 산소투과성, 안정성 등을 검토하는 것을 바탕으로 우수한 선택성 산소투과막을 개발하는 것을 목적으로 한다.

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Advances in the understanding of molybdenum effect on iodine and caesium reactivity in condensed phase in the primary circuit in nuclear severe accident conditions

  • Gouello, Melany;Hokkinen, Jouni;Karkela, Teemu
    • Nuclear Engineering and Technology
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    • v.52 no.8
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    • pp.1638-1649
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    • 2020
  • In the case of a severe accident in a Light Water Reactor, the issue of late release of fission products, from the primary circuit surfaces is of particular concern due to the direct impact on the source term. CsI is the main iodine compound present in the primary circuit and can be deposited as particles or condensed species. Its chemistry can be affected by the presence of molybdenum, and can lead to the formation of gaseous iodine. The present work studied chemical reactions on the surfaces involving gaseous iodine release. CsI and MoO3 were used to highlight the effects of carrier gas composition and oxygen partial pressure on the reactions. The results revealed a noticeable effect of the presence of molybdenum on the formation of gaseous iodine, mainly identified as molecular iodine. In addition, the oxygen partial pressure prevailing in the studied conditions was an influential parameter in the reaction.

Carrier Ethernet for Next Generation Network Infrastructure (차세대 네트워크 인프라를 위한 캐리어 이더넷 기술)

  • Joo, S.S.;Ahn, K.H.;Lee, Y.K
    • Electronics and Telecommunications Trends
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    • v.21 no.6 s.102
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    • pp.64-76
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    • 2006
  • 최초의 이더넷 IEEE 표준인 48비트 주소체계와 버스 토폴로지를 갖는 10Mbps 이더넷이 1985년에 승인받은 이후, 이더넷 기술은 1995년 100Mbps 이더넷, 1998년 1Gbps 이더넷, 2002년 10G 이더넷 표준 등장으로, 전송 용량을 10배씩 높이는 기술 발전이 표준으로 완성까지 시간이 오히려 짧아질 정도로 숨가쁘게 진화를 거듭하였다. 이더넷 전송 용량의 급속한 증가는 LAN과 WAN간 액세스 속도 차이를 급속하게 줄이는 결과를 가져와, 그렇지 않아도 대역폭 제한과 유연성 결여로 문제가 되던 전통적인last mile WAN 서비스를 대체하는 것을 시작으로 결국에는 pure Ethernet WAN transport 기술로 캐리어 이더넷이라는 새로운 이더넷 적용 분야가 등장하게 되었다. 이 글에서는 캐리어 이더넷 네트워크 서비스의 출현 과정과 서비스 특징을 소개하며, 캐리어 이더넷 네트워크 구조 관련 요소 기술로 이더넷의 백본 확장 기술, OAM, resilience, QoS 기술 동향을 정리하고, 마지막으로 캐리어 이더넷 개발 현황과 향후발전 전망에 대하여 살펴본다.

Visualization of blood sucking phenomena of a female mosquito (암 모기 흡혈과정 가시화)

  • Kim, Bo-Heum;Lee, Sang-Joon
    • 한국가시화정보학회:학술대회논문집
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    • 2007.11a
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    • pp.114-115
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    • 2007
  • As a carrier of malaria and sneak of blood, mosquitoes are regarded as an unpleasant insect. However, there are novel phenomena that happen inside a mosquito. Among them, we focused on the blood sucking function of a female mosquito. The main objective of this study was to investigate the mosquito's pumping mechanism in order to resolve the problem encountered when we inject or transport biologic fluids into a micro-chip. To analyze the pumping mechanism, we visualized the blood sucking process inside a female mosquito. Flow characteristics of blood flow in a proboscis were investigated experimentally using a micro-PIV velocity field measurement technique. The anatomical variation of head, thorax, abdomen which work as pumps and valves, was visualized using the syncrotron X-ray micro-imaging technique.

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General Pharmacology of PEG-Hemoglobin SB1

  • Kim, Eun-Joo;Lee, Rae-Kyong;Bak, Ji-Yeong;Choi, Gyu-Kap
    • Biomolecules & Therapeutics
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    • v.7 no.2
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    • pp.170-177
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    • 1999
  • PEG-hemoglobin SB1 (SB1), which is a hemoglobin-based oxygen carrier, is intended to use as a safe blood substitute against brain ischemia and stroke. The general pharmacological profiles of SB1 were studied. The doses given were 0, 5, 10, 20 ml/kg and drugs were administered intravenously. The animals used for this study were mouse, rat and guinea pig. SB1 showed no effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital sleeping time, anticonvulsant activity, analgesic activity, blood pressure and heart rate, left ventricular peak systolic pressure, left ventricular end diastolic pressure, left ventricular developing pressure, double product, heart rate, coronary flow rate, smooth muscle contraction using guinea pig ileum, gastrointestinal transport, gastric secretion, urinary volume and electrolyte excretion at all doses tested except the decrease of body temperature. These findings demonstrated that SB1 possesses no general pharmacological effects at all doses tested.

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NANOCAD Framework for Simulation of Quantum Effects in Nanoscale MOSFET Devices

  • Jin, Seong-Hoon;Park, Chan-Hyeong;Chung, In-Young;Park, Young-June;Min, Hong-Shick
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.6 no.1
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    • pp.1-9
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    • 2006
  • We introduce our in-house program, NANOCAD, for the modeling and simulation of carrier transport in nanoscale MOSFET devices including quantum-mechanical effects, which implements two kinds of modeling approaches: the top-down approach based on the macroscopic quantum correction model and the bottom-up approach based on the microscopic non-equilibrium Green’s function formalism. We briefly review these two approaches and show their applications to the nanoscale bulk MOSFET device and silicon nanowire transistor, respectively.

Theoretical and Experimental Analysis of Back-Gated SOI MOSFETs and Back-Floating NVRAMs

  • Avci, Uygar;Kumar, Arvind;Tiwari, Sandip
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.4 no.1
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    • pp.18-26
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    • 2004
  • Back-gated silicon-on-insulator MOSFET -a threshold-voltage adjustable device-employs a constant back-gate potential to terminate source-drain electric fields and to provide carrier confinement in the channel. This suppresses shortchannel effects of nano-scale and of high drain biases, while allowing a means to threshold voltage control. We report here a theoretical analysis of this geometry to identify its natural length scales, and correlate the theoretical results with experimental device measurements. We also analyze experimental electrical characteristics for misaligned back-gate geometries to evaluate the influence on transport behavior from the device electrostatics due to the structure and position of the back-gate. The backgate structure also operates as a floating-gate nonvolatile memory (NVRAM) when the back-gate is floating. We summarize experimental and theoretical results that show the nano-scale scaling advantages of this structure over the traditional front floating-gate NVRAM.