• 한국재료학회지
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• 제24권6호
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• pp.285-292
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• 2014

Commercial activated-carbon used as the electrode material of an electric double-layer capacitor (EDLC) was posttreated with various acids and alkalis to increase its capacitance. The carbon samples prepared were then heat-treated in order to control the amount of acidic functional groups formed by the acid treatments. Coin-type EDLC cells with two symmetric carbon electrodes were assembled using the prepared carbon materials and an organic electrolyte. The electrochemical performance of the EDLC was measured by galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. Among the various activated carbons, the carbon electrodes (CSsb800) prepared by the treatments of coconutshell-based carbon activated with NaOH and $H_3BO_5$, and then heat treated at $800^{\circ}C$ under a flow of nitrogen gas, showed relatively good electrochemical performance. Although the specific-surface-area of the carbon-electrode material ($1,096m^2/g$) was less than that of pristine activated-carbon ($1,122m^2/g$), the meso-pore volume increased after the combined chemical and heat treatments. The specific capacitance of the EDLC increased from 59.6 to 74.8 F/g (26%) after those post treatments. The equivalent series resistance of EDLC using CSsb800 as electrode was much lower than that of EDLC using pristine activated carbon. Therefore, CSsb800 exhibited superior electrochemical performance at high scan rates due to its low internal resistance.

• 전력전자학회논문지
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• 제21권4호
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• pp.290-295
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• 2016

Socket-outlets and plugs are essential devices that supply electric power into user appliances. During plug-out operation of an engaged plug from the socket-outlet, the consistent arc between the plug and the socket-outlet could develop into heavy fires in DC systems but only a small spark in AC systems. This paper proposes a pre-/post-electrode method to prevent plugs and socket-outlets from melting by sustaining arc energy. To implement the proposed pre-/post-electrodes, an experimental plug is manufactured with two electrodes, in which a post resistance Rs is connected in between. This paper investigates the function of the post resistance Rs, in which the best value of the post resistance Rs is obtained through simulation and experiment.

• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.357-362
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• 2007

AZO(Aluminum-doped Zinc Oxide) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with ITO(Indium Tin Oxide). AZO films have been deposited on glass (corning 1737) substrates by RF magnetron sputtering. The AZO film was post-annealed at $600^{\circ}C$ for 2 hr with $N_2$ atmosphere. The AZO films were used as an anode contact to fabricate OLEDs(Organic Light Emitting Diodes). OLEDs with $AZO/TPD/Alq_3/Al$ configuration were fabricated by thermal evaporation. We investigated that the electric, structural and optical properties of AZO thin films, which measured using the methods of XRD, SEM, Hall measurement and Spectrophotometer. The current density-voltage and luminescence-voltage properties of devices were studied and compared with ITO devices fabricated under the same conditions.

• Journal of Information Display
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• 제7권1호
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• pp.1-6
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• 2006

A 10" carbon nanotube field emission display device was fabricated with a novel structure with a hopping electron spacer (HES) by screen printing technique. HES plays a role of preventing the broadening of electron beams emitted from carbon nanotubes without electrical discharge during operation. The structure of the novel tetrode is composed of carbon nanotube emitters on a cathode electrode, a gate electrode, an extracting electrode coated on the top side of a HES, and an anode. HES contains funnel-shaped holes of which the inner surfaces are coated with MgO. Electrons extracted through the gate are collected inside the funnel-shaped holes. They hop along the hole surface to the top extracting electrode. In this study the effects of the addition of HES on emission characteristics of field emission display were investigated. An active ozone treatment for the complete removal of residues of organic binders in the emitter devices was applied to the field emission display panel as a post-treatment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.313-316
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• 1997

The effects of aromatic curing agent of MDA contents and post curing conditions on dielectric deterioration characteristics of DGEBA/MDA/SN system were investigated. The dielectric properties were measured by using needle-plane electrode geometry under the commercial AC high electric field application. As the curing agent content increased, the dielectric breakdown strength increased and then decreased slightly. All the trees initiated from the tip of needle electrode and the shape of the tree in this system was a dendrite type.

• 한국표면공학회지
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• 제56권5호
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• pp.320-327
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• 2023

In this study, the nickel hydroxide (Ni(OH)₂) electrode for supercapacitor was prepared via hydrothermal method. Based on the nickel (Ni) foam, the electrode does not require any additional binder material or post-processing. Nickel nitrate (Ni(NO₃)₂) and hexamethylenetetramine (C₆H₁₂N₄) were used for synthesis, and the synthesis condition was 12 hours at 80 ℃. X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) were used to analyze the structural characteristics of the electrode, and it shown that the nickel hydroxide was successfully prepared after only the one-step hydrothermal synthesis. The electrochemical properties were analyzed through the half-cell test. The prepared electrode shown a pair of oxidation/reduction peaks, indicating that the driving method included the redox reaction on the electrode surface. After the charge/discharge test, the specific capacitance was calculated as the value of 438 F/g at 3 A/g.

• Journal of Welding and Joining
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• 제17권5호
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• pp.83-88
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• 1999

In this paper resistance projection weldability of Zn coated steels with post treatment has been discussed. Projection welding was performed by a condenser discharge type power source which was equipped with welding parameter monitoring system. Mechanical test results indicated that the effect of post coatings on the projection front changed showing very small very small spattering at the weld strength was negligible. However, contamination rate of the block electrode varied depending on the post treatment coatings. Test results also showed that projection height before welding should be kept to be 80-100% of the specimen thickness as far as the surface quality was taken into consideration. Based on the high speed photography, discharge condition at the beginning stage of the welding process. It was considered that the spattering reduced the weld strength slightly at the optimum heat input range.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1950-1953
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• 1996

A $1\;{\times}\;4$ micro mirror array is designed and fabricated. In contrast to other micro mirrors which utilize torsional flexure hinges or cantilevers for restoring torque and supporting purpose, we have placed a substrate hinge structure under each mirror. Each micro mirror consists of address electrode, substrate hinge consisting of pin and staple, supporter post, and mirror plate. Electrical connection between mirror plate and ground electrode is established by substrate hinge. Mirror undergoes a rotational motion due to electrostatic force when voltage difference is applied between address electrode and mirror plate. Micro mirrors with two different types of staple shape and two different pin sizes are designed and fabricated. Each mirror is designed to have ${\pm}\;10^{\circ}$ of deflection angle and have $100\;{\times}\;110\;{\mu}m^2$ of size.

• 한국전기전자재료학회논문지
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• 제11권3호
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• pp.229-236
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• 1998

Ferroelectric $Sr_xBi_yTa_2O_{9+\alpha}$/(0.7$\leqSr\leq1.0,\; 2.0\leqBi\leq2.6)$ solutions were prepared by MOD (Metalorganic Deposition) process. These solutions were made into thin films with thickness ranging from 1500~2000${\AA}$ by spin coating. The phase transformation of the SBT thin films by variation of annealing temperature and annealing time were observed using high temperature XRD and SEM. The crystallization and grain growth of SBT thin film were accomplished at $800^{\circ}C$ for 30 minutes after deposition of Pt top electrode by sputtering to prevent electrical breakdown. Ferroelectric properties of the SBT thin films were measured in the range of $\pm$3V\; and\; \pm5V$. The specimen with composition ratio of Sr/Bi/Ta (0.8/2.4/2.0) has the excellent ferroelectric properties ; $2P_r = 10.5,\; 13.2\muC/cm^2 \;at\; \pm3V\; and\; \pm5V$ respectively. Observing the post annealed Pt/SBT/Pt interface by SEM, it was found that Pt electrode sputtered on to the SBT thin film penetrated into the hollow on the SBT thin film, thus decreasing the effective insulation thickness. The effective insulation thickness recovered by post annealing, and this was confirmed by leakage current density measurement.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제37회 하계학술대회 초록집
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• pp.395-395
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• 2009