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http://dx.doi.org/10.4313/JKEM.2008.21.10.938

Electrical and Optical Properties of Semitransparent Metal Electrodes for Top-emission Organic Light-emitting Diodes  

Shin, Eun-Chul (홍익대학교 정보디스플레이공학과)
An, Hui-Chul (홍익대학교 정보디스플레이공학과)
Kim, Tae-Wan (홍익대학교 정보디스플레이공학과)
Publication Information
Journal of the Korean Institute of Electrical and Electronic Material Engineers / v.21, no.10, 2008 , pp. 938-942 More about this Journal
Abstract
Electrical and optical properties of semitransparent Ag and Al layer were studied, which are used for the electrodes in top-emission organic light-emitting diodes. Sheet resistance and transmittance of visible light through a thin layer were measured and analyzed. Several thin metal layers of Ag and Al were deposited onto a glass substrate up to a thickness of 50 nm using a thermal evaporation. Sheet resistance measurements show that a layer thickness is needed more than 15 nm and 20 nm for Ag and Al, respectively, when a proper sheet resistance is assumed to be less than $50{\Omega}/sq$. From the measurements of transmittance of visible light through a thin-metal layer, metallic behavior was observed when the layer thickness is over 25 nm for both films. Thus, from a study of sheet resistance and transmittance of visible light, a minimum proper thickness of semitransparent metal layer is 20 nm and 25 nm for Ag and Al, respectively.
Keywords
Organic light-emitting diodes; Top omission; Transmittance; Sheet resistance;
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