• Title/Summary/Keyword: Oxide anodes

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Efficient Organic Light-emitting Diodes with Aluminum-doped Zinc Oxide Anodes (알루미늄 도핑된 산화아연 양극을 적용한 고효율 유기발광다이오드)

  • Lee, Ho-Nyeon;Lee, Young-Gu;Jung, Jong-Guk;Lee, Seung-Eui;Oh, Tae-Sik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.8
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    • pp.711-715
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    • 2007
  • Properties of organic light-emitting diodes (OLEDs) with aluminum-doped zinc oxide (ZnO:Al) anodes showed different behaviors from OLEDs with indium tin oxide (ITO) anodes according to driving conditions. OLEDs with ITO anodes gave higher current density and luminance in lower voltage region and better EL and power efficiency under lower current density conditions, However, OLEDs with ZnO:Al anodes gave higher current density and luminance in higher voltage region over about 8V and better EL and power efficiency under higher current density over $200mA/cm^2$. These seemed to be due to the differences in conduction properties of semiconducting ZnO:Al and metallic ITO. OLEDs with ZnO:Al anodes showed nearly saturated efficiency under high current driving conditions compared with those of OLEDs with ITO anodes. This meant better charge balance in OLEDs with ZnO:Al anodes. These properties of OLEDs with ZnO:Al anodes are useful in making bright display devices with efficiency.

Fabrication of LaySr1-yFexTi1-xO3-based Nanocomposite Solid Oxide Fuel Cell Anodes by Infiltration (Infiltration법을 이용한 LaySr1-yFexTi1-xO3계 나노복합 연료극 제조)

  • Yoon, Jong-Seol;Choe, Yeong-Ju;Hwang, Hae-Jin
    • Journal of the Korean Ceramic Society
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    • v.51 no.3
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    • pp.224-230
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    • 2014
  • Nano-sized gadolinium-doped ceria (GDC)/nickel particle-dispersed $La_ySr_{1-y}Ti_{1-x}Fe_xO_3$ (LSFTO)-based composite solid oxide fuel cell anodes were fabricated by an infiltration method and the effects of the GDC/Ni nanoparticles on the anode polarization resistance and cell performance were investigated in terms of the infiltration time and nickel content. The anodic polarization resistance of the LSFTO anode was significantly enhanced by GDC and/or Ni infiltration and it decreased with increasing infiltration time and Ni content, respectively. It is believed that the observed phenomena are associated with enhancement of the ionic conductivity and catalytic activity in the nanocomposite anodes by the addition of GDC and Ni. Power densities of cells with the LSFTO and LSFTO-GDC/Ni nanocomposite anodes were 150 and $300mW/cm^2$ at $800^{\circ}C$, respectively.

Preparation and Characterization of Insoluble Anodes for Electrodeposition of Ni-W Alloys in Ammoniacal Citrate Bath (Ni-W 합금도금용 불용성 양극의 제조 및 특성 연구)

  • 장도연;강성군
    • Journal of Surface Science and Engineering
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    • v.32 no.6
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    • pp.686-694
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    • 1999
  • Insoluble anodes of the Ta/Ir mixed metal oxide for electrodeposition of Ni-W alloy in ammoniacal citrate bath were prepared by thermal decomposition method. Ti plate was etched in boiling oxalic acid solution and coated with ethanol solution of $TaCl_{5}$ and $IrCl_4$ mixed in a fixed ratio, followed by drying and treating at various temperatures. The coating layer of these insoluble anode was characterized by SEM, EDX, XRD and DSC. The decomposition rate of citric acid in plating bath was determined by measuring the $CO_2$ gas evolved at the anodes with Gas Chromatography. Evolution of $CO_2$ gas from Ta/Ir oxide anodes decreased about 5% compared with that of Pt. The $CO_2$ gas evolution was increased with the amount of Ir-oxide in the coatings. The coatings which have more than 40% ratio of Ta content and heat-treated at the temperature higher than $400^{\circ}C$ showed better efficiency

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Lifetime of Insoluble Anode for Cathodic Protection on Concrete Construction

  • Sohn, Kicheon;Chang, Hyunyoung;Kim, Youngsik
    • Corrosion Science and Technology
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    • v.4 no.2
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    • pp.56-59
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    • 2005
  • In rebar concrete structure, the corrosion of rebar can arise the deterioration of concrete structure and may affect the safety of the whole system. Recently, several methods for corrosion protection have been used and are more important for concrete structure using the sand including chloride ion. Among several protections, electrical cathodic protection has been expected to be one of the most useful methods in corrosion protection for reinforcement of concrete structures. The anode for cathodic protection needs high current density, high corrosion resistance and low overvoltage. To fill up the special qualities, the insoluble anodes were developed and these anodes were coated with metal oxide of $TiO_2$, $ZrO_2$, $RuO_2$, and $IrO_2$. Lifetime of these anodes can be one of the important factors affecting the lifetime of concrete structure in cathodic protection. In this work, several anodes were made by sol-gel method and thermal decomposition method and the lifetime of these anodes was evaluated by NACE international standard test method, TM 0294-94. Also, we did analyze the properties of coated metal oxides.

Flexible Organic Light-Emitting Diodes Using Modified Graphene Anodes

  • Han, Tae-Hui;Lee, Yeong-Bin;Choe, Mi-Ri;U, Seong-Hun;Bae, Sang-Hun;Hong, Byeong-Hui;An, Jong-Hyeon;Lee, Tae-U
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.69.2-69.2
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    • 2012
  • Graphene films have a strong potential to replace indium tin oxide anodes in organic light-emitting diodes (OLEDs), to date. However, the luminous efficiency of OLEDs with graphene anodes has been limited by a lack of efficient methods to improve the low work function and reduce the sheet resistance of graphene films to the levels required for electrodes. Here, we fabricate flexible OLEDs by modifying the graphene anode to have a high work function and low sheet resistance, and thus achieve extremely high luminous power efficiencies (37.2 lm/W in fluorescent OLEDs, 102.7 lm/W in phosphorescent OLEDs), which are significantly higher than those of optimized devices with an indium tin oxide anode (24.1 lm/W in fluorescent OLEDs, 85.6 lm/W in phosphorescent OLEDs). We also fabricate flexible white OLED lighting devices using the graphene anode. These results demonstrate the great potential of graphene anodes for use in a wide variety of high-performance flexible organic optoelectronics.

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Sample Preparation for Microstructural Characterization of Ni-Yttria-Stabilized Zirconia Anodes

  • Sim, Soo-Man
    • Journal of the Korean Ceramic Society
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    • v.55 no.4
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    • pp.376-380
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    • 2018
  • Microstructural characterization of Ni-yttria-stabilized zirconia (YSZ) anodes using secondary electron images has been limited by a lack of contrast between Ni and YSZ phases. This paper reports a sample preparation method for obtaining secondary electron images that allow the detection of Ni, YSZ, and pore phases together. Ni-YSZ anode samples were obtained by reducing NiO-YSZ samples prepared by using the mixed oxide method. Colloidal silica polishing and electrolytic etching were performed on the Ni-YSZ samples. The morphological change of the sample surface after each polishing process is examined.

Plasma treatments of indium tin oxide(ITO) anodes in argon/oxygen to improve the performance and morphological property of organic light-emitting diodes(OLED) ($O_2$ : Ar 혼합가스 플라즈마로 ITO표면 처리한 OLED의 동작특성 향상과 표면개질에 관한 연구)

  • Seo, Yu-Suk;Moon, Dae-Gyu;Jo, Nam-Ihn
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.04a
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    • pp.67-68
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    • 2008
  • A simple bi-layer structure of organic light emitting diode (OLED) was used to study the characteristics of anode preparation. Indium tin oxide (ITO) anode surface treatment of OLEDs was performed to get the optimum condition for the ITO anode. The ITO surface was treated by $O_2$ or $O_2$ / Ar mixed gas plasma with different processing time. The electrical characteristics of OLED were improved by plasma treatment. The operating voltage of OLED with $O_2$ or $O_2$/Ar mixed gas plasma treated anodes decreases from 8.2 to 3.4 V and 3.2V, respectively. The $O_2$ /Ar mixed gas plasma treatment results in better electrical property.

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Characterization and Fabrication of La(Sr)Fe(Co)O3-δ Infiltrated Cathode Support-Type Solid Oxide Fuel Cells (La(Sr)Fe(Co)O3-δ 침지법을 이용한 양극 지지형 SOFC 제조 및 출력 특성)

  • Hwang, Kuk-Jin;Kim, Min Kyu;Kim, Hanbit;Shin, Tae Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.6
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    • pp.501-506
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    • 2019
  • To overcome the limitations of the conventional Ni anode-supported SOFCs, various types of ceramic anodes have been studied. However, these ceramic anodes are difficult to commercialize because of their low cell performances and difficulty in manufacturing anode-support typed SOFCs. Therefore, in this study, to use these ceramic anodes and take advantage of anode-supported SOFC, which can minimize ohmic loss from the thin electrolyte, we fabricated cathode support-typed SOFC. The cathode-support of LSCF-YSZ was prepared by the acid treatment of conventional Ni-YSZ (Yttria-stabilized Zirconia) anode-support, followed by the infiltration of LSCF to YSZ scaffold. The composite of $La(Sr)Ti(Ni)O_3$ and $Ce(Mn,Fe)O_2$ was used as the ceramic anode. The fabricated cathode-supported button cell showed a relatively low power density of $0.207Wcm^{-2}$ at $850^{\circ}C$; however, it is expected to show better performance through the optimization of the infiltration rate and thickness of LSCF-YSZ cathode-support layer.

Impedance spectroscopy analysis of organic light emitting diodes with the $CF_4$ anode plasma treatment ($CF_4$ 플라즈마 처리된 ITO박막을 이용한 유기 EL 소자의 성능향상에 관한 임피던스 분석)

  • Park, Hyung-June;Kim, Hyun-Min;Lee, Jun-Sin;Sohn, Sun-Young;Jung, Dong-Geun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.320-321
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    • 2006
  • In this work, impedance Spectroscopic analysis was applied to study the effect of plasma treatment on the surface of indium-tin oxide (ITO) anodes using $CF_4g$ as and to model the equivalent circuit for organic light emitting diodes (OLEDs) with the $CF_4$ plasma treatment of ITO surface at the anodes. This device with ITO/TPD/$Alq_3$/LiF/Al structure can be modeled as a simple combination of a resistor and a capacitor. The $CF_4$ plasma treatment on the surface of ITO shifts the vacuum level of the ITO as a result of which the barrier height for hole injection at the ITO/organic interface is reduced. The Impedance spectroscopy measurement of the devices with the $CF_4$ plasma treatment on the surface of ITO anodes shows change of values in parallel resistance ($R_p$) and parallel capacitance ($C_p$).

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Impedance spectroscopy analysis of organic light emitting diodes with the $O_2$ anode plasma treatment (저압 산소 플라즈마 처리된 ITO박막을 이용한 유기 EL 소자의 성능 향상에 관한 임피던스 분석)

  • Kim, Hyun-Min;Park, Hyung-June;Lee, Jun-Sin;Oh, Se-Myoung;Jung, Dong-Ggeun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.06a
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    • pp.436-437
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    • 2006
  • In this work, impedance Spectroscopic analysis was applied to study the effect of plasma treatment on the surface of indum-tin oxide (ITO) anodes using $O_2$ gas and to model the equivalent circuit for organic light emitting diodes (OLEDs) with the $O_2$ plasma treatment of ITO surface at the anodes. This device with ITO/TPD/Alq3/LiF/Al structure can be modeled as a simple combination of a resistor and a capacitor. The $O_2$ plasma treatment on the surface of ITO shifts the vacuum level of the ITO as a result of which the barrier height for hole injection at the ITO/organic interface is reduced. The impedance spectroscopy measurement of the devices with the $O_2$ plasma treatment on the surface of ITO anodes shows change of values in parallel resistance ($R_p$) and parallel capacitance ($C_p$).

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