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Pohang, South Korea

Jeong J.-H.,Sunchon National University | Song M.-H.,Sunchon National University | Chung H.-B.,Sunchon National University | Lee M.-S.,Sunchon National University | And 8 more authors.
Korean Chemical Engineering Research | Year: 2015

Recently, direct formic acid fuel cells (DFAFC) among direct liquid fuel cells is studied actively. Economical hydrocarbon membranes alternative to fluorinated membranes for DFAFC's membrane are receiving attention. In this study, characteristics of sulfonated poly(ether ether ketone, sPEEK) and sulfonated poly(arylene ether sulfone, PAES) membranes were compared with Nafion membrane at DFAFC operation condition. Formic acid crossover current density of hydrocarbon membranes were lower than that of Nafion 211 fluorinated membrane. I-V performance of sPEEK MEA(Membrane and Electrode Assembly) was similar to that of Nafion 211 MEA due to similar membrane resistance each other. sPEEK MEA with low formic acid crossover showed higher stability compared with Nafion 211 MEA.

Park E.-K.,Sungkyunkwan University | Kim J.-H.,Sungkyunkwan University | Lee D.-H.,Sungkyunkwan University | Kim K.-S.,Kolon Research Institute | And 3 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2015

Printed electronics have surfaced with a lot of interest recently. This paper reports development of a non vacuum process for fabricating poly(3-hexylthiophene):[6,6]-pheny-C61-butyric acid methyl ester organic solar cells (OSCs) using ink-jet printing technique. The printing conditions of different layers were optimized to avoid the coffee ring effect and the Marangoni effect. The effect of substrate's temperature and drop spacing size was compared to obtain uniform layers. We controlled the substrate temperature ranging from 30 °C to 80 °C and varied the spacing size between two lines ranging from 10 μm to 80μm during printing. The device characteristics were analyzed using alpha step and solar simulator. The optimized printed conditions for ZnO are 50 °C substrate temperature and 50 μm spacing size. For the active layer, PEDOT:PSS and Ag electrode, the optimized conditions are 50 DC/50 μm, 30 °C/30μm and 80 °C/80 μm, respectiveiely. The power conversion efficiency of the OSCs fabricated with optimized printing condition is 1.25%. © 2015 American Scientific Publishers.

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