• Title/Summary/Keyword: Kelvin-probe method

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Nano-size Study of Surface-modified Ag Anode for OLEDs (표면처리에 의한 유기발광소자(OLED)용 Ag 전극의 Nano-size 효과 연구)

  • Kim, Joo-Young;Kim, Soo-In;Lee, Kyu-Young;Kim, Hyeong-Keun;Jun, Jae-Hyeok;Jeong, Yun-Jong;Kim, Mu-Chan;Lee, Jong-Rim;Lee, Chang-Woo
    • Journal of the Korean Vacuum Society
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    • v.21 no.1
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    • pp.12-16
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    • 2012
  • Although silver is used for T-OLED (Top emitting organic Light-Emitting Diode) as reflective anode, it is not an ideal material due to its low work function. Thus, we study the effect of annealing and atmospheric pressure plasma treatment on Ag film that increases its work function by forming the thin silver oxide layer on its surface. In this study, we deposited silver on glass substrate using RF sputtering. Then we treated the Ag samples annealing at $300^{\circ}C$ for 30 minutes in atmosphere or treating the atmospheric plasma treatment for 30, 60, 90, 120s, respectively. We measured the change of the mechanical properties and the potential value of surface with each one at a different treatment type and time. We used nano-indenter system and KPFM (Kelvin Probe Force Microscopy). KPFM method can be measured the change of surface potential. The nanoindenter results showed that the plasma treatment samples for 30s, 120s had very low elastic modulus, hardness and Weibull modulus. However, annealed sample and plasma treated samples for 60s and 90s had better mechanical properties. Therefore, plasma treatment increases the uniformity thin film and the surface potential that is very effective for the performace of T-OLED.

Effect of wet/dry transition on the atmospheric corrosion of Zn (아연의 대기부식에 미치는 주기적 침적/건조 효과)

  • Kim, Ki-Tae
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 1998.05a
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    • pp.3-3
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    • 1998
  • The atmospheric corrosIOn properties of Zinc (Zn) under wet/dry transition of $H_20$ film were investigated in this study. The atmospheric corrosion of metal is usually occurred as a result of repetitious thickness transition (so called wet/dry transition) of liquid phase which is covering the metal surface. Corrosion potential and the polarization behaviour of Zn during liquid film thickness transition were measured by Kelvin probe method which IS using vibrating reference electrode without touching the liquid film. The oxidized states of Zn as a result of successive wet/dry transition were also investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that the corrosion potential and the corrosIOn rate of Zn both are increasing during drying. However, the corrOSIon rate is decreasing again when the Zn surface is completely dried while the corrosion potential still remains high. This behaviour can be explained by the polarization behaviour change of Zn according to the $H_20$ film thickness change. The completely dried surface is consisted mostly with Zn and ZnO phases. After a number of cycles of wet/dry transition, however, the oxidized Zn phase of ${\varepsilon}-Zn(OH)_2$, which has rather voluminous and defected structure, were found.

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Surface Potential Properties of CuPc/Au Device with Different Substrate Temperature (CuPe/Au 소자의 기판 온도 변화에 따른 표면전위 특성)

  • Lee, Ho-Shik;Park, Yong-Pil;Kim, Young-Pyo;Cheon, Min-Woo;Yu, Seong-Mi
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2007.10a
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    • pp.758-760
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    • 2007
  • Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with different metal electrode. So we need the effect of the substituent group attached to the phthalocyanine on the surface potential was investigated by Kelvin probe method with varying temperature of the substrate. We were obtained the positive shift of the surface potential for CuPc thin film. We observed the electron displacement at the interface between Au electrode and CuPc layer and we were confirmed by the surface potential measurement.

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