• Title/Summary/Keyword: Cathode interface

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Effects of Alloying Elements on the Corrosion Layer Formation of Pb-Grid/Active Materials Interface (Pb 기판/활물질 계면의 부식층형성에 미치는 합금원소영향)

  • Oh, Se-Woong;Choe, Han-Cheol
    • Journal of the Korean institute of surface engineering
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    • v.40 no.5
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    • pp.225-233
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    • 2007
  • Effects of alloying elements on the corrosion layer formation of Pb-grid/active materials interface has been researched for improvement of corrosion resistance of Pb-Ca alloy. For this research, various amounts of alloying elements such as Sn, Ag and Ba were added to the Pb-Ca alloys and investigated their corrosion behaviors. Batteries fabricated by using these alloys as cathode grids were subjected to life cycle test. Overcharge life cycle test was carried out at $75^{\circ}C$, 4.5 A, for 110 hrs. with KS standard (KSC 8504). And then, after keeping the battery with open circuit state for 48 hr, discharge was carried out at 300A for 30 sec. Corrosion morphology and interface between Pb-grid and active materials were investigated by using ICP, SEM, WDX, and LPM. Corrosion layer of Pb-Ca alloy got thicken with increasing Ca content. For Pb-Ca-Sn alloy, thickness of corrosion layer decreased as Sn and Ag content increased gradually. In case of Pb-Ca-Sn-Ba alloy, thickness of corrosion layer decreased up to 0.02 wt% Ba addition, whereas, it was not changed in case of above 0.02 wt% Ba addition.

Flip Chip Interconnection-UBM and Material Issues

  • Jang, Se-Young
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.09a
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    • pp.193-215
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    • 2003
  • Fracture Mechanism of Flip Chip Electromigration Failure - Mostly caused by Cathode Depletion at the UBM/Solder Interface Guideline to Increase Electromigration Resistance Material Selection: Sn/Ag(/Cu) > Pb/63Sn Cu UBM > Ni UBM (but, Solder Material combination) UBM Design: thick UBM is preferable (but, Stress Issue) Pad open/UBM size: as large as possible (but, pad size & pitch limit)

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Development of Blue Organic Light-Emitting Diodes(OLEDs) Due to Change in Mixed Ratio of HTL:EML(DPVBi:NPB) Layers (HTL:EML(DPVBi:NPB) 층의 조성비 변화에 따른 청색 유기 발광 소자 개발)

  • Lee, Tae-Sung;Lee, Byoung-Wook;Hong, Chin-Soo;Kim, Chang-Kyo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04a
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    • pp.31-32
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    • 2008
  • The structure of OLEDs with conventional heterostructure consists of anode, hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, and cathode. NPB used as a hole transport layer and DPVBi used as a blue light emitting layer were graded-mixed at selected ratio. Interface at heterojunction between the hole transport layer and the elecrtron transport layer restricts device's stability. Mixing of the hole transport layerand the emitting layer removes abrupt interface between the hole transport. layer and the electron transport layer. The stability of OLED with graded mixed-layer developed in this study was improved.

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A Characterization on Organic Electro-luminescence (유기 전기 luminescence 다이오드 특성)

  • Lee, Han-Seong
    • Proceedings of the KIEE Conference
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    • 2007.11c
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    • pp.165-169
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    • 2007
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made food electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

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Electrochemical spike oscillation st the Ni electrode interface (Ni 전극 계면에서 전기화학적 spike 발진)

  • 천장호;손광철;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.12
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    • pp.83-89
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    • 1996
  • The electrochemical spike oscillations at the nickel (Ni) electrode/(0.05M KHC$_{8}$H$_{4}$O$_{4}$) buffer solution (pH 9) interface have been studied using voltammetric and chronoamperometric methods. The nature of the periodic cathodic current spikes is the activation controlled currents due to the hydrogen evolution reaction and depends onthe fractioanl surface coverage of the adsorbed hydrogen intermediate or the cathodic potential. There is two kinds of the waveforms corresponding to two kinds of the cathodic current spike oscillations. The widths, periods, and amplitudes of the cathodic current spikes are 4 ms or 5ms, 151 ms or 302 ms, and < 30 mA or < 275 mA, respectively. The fast discharge and recombination reaction steps are 1.5 times and twice and faster than the slow discharge and recombination reaction steps. The fast and slow discharge and recombination reaction steps are 1.5 times and twice faster than the slow discharge and recombination reaction steps. The fast and slow discharge and recombination reactions corresponding to the fast and slow adsorption sites at the Ni cathode.

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Chemical structure of the bilayer $Ag/Li_2O$ cathode interface in organic light-emitting diodes

  • Joo, Min-Ho;Baik, Min-Kyung;Choi, Jong-Kwon;Park, Kyu-Ho;Lee, Jay-Man;Kim, Myung-Seop;Yang, Joong-Hwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.1006-1009
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    • 2006
  • The chemical structure of the interface between Ag with $Li_2O$ and tri (8-hydroxyquinoline) aluminum (Alq) was investigated by using in-situ characterization of x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). $Li_2O$ on Ag had lower barrier height than LiF on Ag. XPS and UPS results show the interaction between $Li_2O$ and Alq leads to gap state formation in HOMO of Alq.

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Development of low power type sensor for the DO concentration measurement by clark electrode (Clark전극에 의한 DO 농도측정을 위한 절전형 센서개발에 관한 연구)

  • 이동희
    • Electrical & Electronic Materials
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    • v.8 no.3
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    • pp.254-260
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    • 1995
  • A method is described for the design and fabrication of the sensor interface circuits on the Clark electrodes for the dissolved oxygen(DO). The discussion includes a method for the +5 V single-supply driving for the sensor circuits, which has low power comsumption for the front-end electronics. DO probe under test is composed of the Clark electrode with silver anode, gold cathode and the electrolyte of half saturated KCI solution and the FEP teflon memtrance for the oxygen penetration. Typical polarograms for the DO probes by using this sensor circuit reveals high accuracy over 99% of the I to V conversion. Partial pressure of oxygen obtained from the polarograms are well suited to the results calculated. It is expected that the proposed sensor circuits can be utilized into the customized IC for the battery-driven small-size DO meters.

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A Research on Organic Electro-luminescence (유기 전기발광 소자에 관한 연구)

  • Lee, Han-Seong
    • Proceedings of the KIEE Conference
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    • 2005.10a
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    • pp.82-85
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    • 2005
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study, we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

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A study on Fabrication and Characterization of Organic Light-Emitting Diodes (유기 발광 다이오드의 제작 및 특성에 관한 연구)

  • Lee, Han-Seong
    • Proceedings of the KIEE Conference
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    • 2008.11b
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    • pp.89-91
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    • 2008
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micro molecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

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A Research on Life of Organic Lumminescence Devices (유기EL 소자의 수명에 관한 연구)

  • Lee, Han-Sung
    • Proceedings of the KIEE Conference
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    • 2002.06a
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    • pp.110-113
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    • 2002
  • Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study. we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO. energy walls in both pole interface. contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer. these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon. and raise a question.

  • PDF