• Title/Summary/Keyword: materials science

Search Result 32,406, Processing Time 0.05 seconds

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
    • /
    • v.4 no.2
    • /
    • pp.47-49
    • /
    • 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.

  • PDF

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
    • /
    • v.4 no.3
    • /
    • pp.78-80
    • /
    • 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.

  • PDF

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

  • Hoseok Lee;Shin-Woo Myeong;Jun-young Park;Eon-ju Park;Sungjun Heo;Nam-In Kim;Jae-hun Lee;Jae-hun Lee;Jae-Yeop Jeong;Song Jin;Jooyoung Lee;Sang Ho Lee;Chiho Kim;Sung Mook Choi
    • Journal of the Korean institute of surface engineering
    • /
    • v.56 no.6
    • /
    • pp.412-419
    • /
    • 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