• 제목/요약/키워드: materials science

검색결과 32,549건 처리시간 0.054초

Research on Powder Metallurgy Technology in Fusion Materials in China

  • Ge, Chang-Chun;Zhou, Zhang-Jian;Du, Juan;Song, Shu-Xiang
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.896-897
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    • 2006

  • In the viewpoint of engineering, materials problem is a key problem, which determines whether the exploitation of fusion energy will be success. The most important class of fusion materials is plasma-facing materials (PFM). W, as high Z high melting-point metal is one of the most important candidate materials due to its high plasma erosion resistance. Improving the ductility of W and W based alloy, lowering its ductile-brittleness transition temperature for meeting the requirements of fusion application is an important task. In this paper, severalpowder meatllurgy methods of fabricating W and W based materials are being investigated.

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Highly transparent Pt ohmic contact to InGaN/GaN blue light-emitting diodes

  • Chul Huh;Kim, Hyun-Soo;Kim, Sang-Woo;Lee, Ji-Myon;Kim, Dong-Joon;Kim, Hyun-Min;Park, Seon-Ju
    • Journal of Korean Vacuum Science & Technology
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    • 제4권2호
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    • pp.47-49
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    • 2000

  • We report on the fabrication and characterization of InGaN/GaN multiple quantum well light emitting diode (LED) with a highly transparent Pt ohmic contact as a current spreading layer. The value of light transmittance of a Pt thin film with a thickness of 8 m on p-GaN was measured to be 85% at 450nm. The peak wavelength and the full-width at half-maximum (FWHM) of the emission spectrum of the LED at 20 mA were 453 m and 23 m, respectively. Pt-contacted LEDs show good electrical properties and high light-output efficiency compared to Ni/Au-contacted ones. These results suggest that a Pt thin film can be used as an effective current spreading layer with high light-transparency.

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Highly transparent Pt ohmic contact to InGaN / GaN blue light - emitting diodes

  • Huh, Chul;Kim, Hyun-Soo;Kim, Sang-Woo;Lee, Ji-Myon;Kim, Dong-Joon;Kim, Hyun-Min;Park, Seong-Ju
    • Journal of Korean Vacuum Science & Technology
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    • 제4권3호
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    • pp.78-80
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    • 2000

  • We reprot on the fabrication and characterization of InGaN/GaN multiple quantum well light-emitting diode (LED) with a highly transparent Pt ohmic contact as a current spreading layer. The value of light transmittance of a Pt thin film with a thickness of 8 nm on-GaN was measured to be 85% at 450 nm. The peak wavelength and the full-width at half-maximum (FWHM) of the emission spectrum of the LED at 20 mA were 453 nm and 23 nm, respectively. Pt-contacted LEDs show good electrical properties and high light-output efficiency compared to Ni/Au-contacted ones. These results suggest that a Pt thin film can be used as an effective current spreading layer with high light-transparency.

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음이온 교환막 수전해 적용을 위한 고균일 고내구 코발트 산화물 전극의 제조 및 공정 조건 최적화 (Optimization of fabrication and process conditions for highly uniform and durable cobalt oxide electrodes for anion exchange membrane water electrolysis)

  • 이호석;명신우;박준영;박언주;허성준;김남인;이재훈;이재훈;정재엽;진송;이주영;이상호;김치호;최승목
    • 한국표면공학회지
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    • 제56권6호
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    • pp.412-419
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    • 2023

  • Anion exchange membrane electrolysis is considered a promising next-generation hydrogen production technology that can produce low-cost, clean hydrogen. However, anion exchange membrane electrolysis technology is in its early stages of development and requires intensive research on electrodes, which are a key component of the catalyst-system interface. In this study, we optimized the pressure conditions of the hot-pressing process to manufacture cobalt oxide electrodes for the development of a high uniformity and high adhesion electrode production process for the oxygen evolution reaction. As the pressure increased, the reduction of pores within the electrode and increased densification of catalytic particles led to the formation of a uniform electrode surface. The cobalt oxide electrode optimized for pressure conditions exhibited improved catalytic activity and durability. The optimized electrode was used as the anode in an AEMWE single cell, exhibiting a current density of 1.53 A cm-2 at a cell voltage of 1.85 V. In a durability test conducted for 100 h at a constant current density of 500 mA cm-2, it demonstrated excellent durability with a low degradation rate of 15.9 mV kh-1, maintaining 99% of its initial performance.

  • https://doi.org/10.5695/JSSE.2023.56.6.412 인용 PDF