• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.1
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• pp.151-155
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• 2007

A compact discharge plasma system with a photocatalyst has been proposed and investigated experimentally for application to air conditioners. It was found that there was intense ultra violet radiation with high energy of 3.2 eV from the corona discharge due to the DC-biased pulse voltage applied on a wire. An electrophotochemical reaction took place apparently on the surfaces of the photocatalyst of $TiO_2$ irradiated ultra violet front the discharge plasma in the proposed plasma system. The proposed discharge plasma system with the photocatalyst of $TiO_2$ showed very high removal efficiency of VOCs by tile additional electrophotochemical reactions on the photocatalyst. The proposed discharge plasma system also showed very high removal efficiency of particles such as smokes, suspended bacteria, and pollen and mite allergens by the electrostatic precipitation part. This type of corona discharge plasma system with a photocatalyst can be used as an effective means of removing both indoor pollutant gases and particles including suspended allergens.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.2004-2009
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• 2007

A new high-speed drive method for the plasma display panel is proposed. In this method, the address period is inserted for the rest period of the sustain pulses and the priming pulse is applied on the entire panel at the same time overlapping with the sustain period. The ramp shaped priming pulse can be made with a simple drive circuit in this technology and the stable sustain discharge can be induced even by a narrow scan pulse in help of the space charge generated from the address discharge. From the experiments, it is ascertained that the priming pulse hardly influences the sustain discharge. Moreover, the voltage margin of the sustain discharge is almost constant though that of the address discharge broadens with narrowing the scan pulse width. And, if the time interval between the scan pulse and the sustain pulse is within $6{\mu}s$, the voltage margin of the address and the sustain discharges are unaffected though the applied position of the scan pulse is changed. High-speed driving with the address pulse of $0.7{\mu}s$ width was achieved and the address voltage margin of 20V and the sustain voltage margin of 10V were obtained.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1830-1833
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• 2002

We measured 3-dimensional temporal behavior of the light emitted from AC plasma display panel(PDP) at various auxiliary voltage pulse width supplied to the address electrode in sustain period using scanned point detecting system. In the case of applying an auxiliary address voltage pulse, the light emission starts at the inner edges of the cathode so the larger discharge volume toward address electrode can be obtained compared with the normal sustain discharge. Especially, when the auxiliary voltage pulse width is the $2{\mu}s$, the maximum luminance and long emission time can be obtained.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.7
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• pp.1218-1222
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• 2008

We investigate the effect of rise time of a pulse bias voltage on atmospheric plasma generation. With the faster rise time of the pulse bias, the glow discharge appears to be more uniformly generated along the electrodes. I-V measurement confirms that higher loading power can be obtained using the faster rise time. A new understanding for atmospheric plasma generation at a micro-gap electrode is suggested.

• Korean Journal of Materials Research
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• v.25 no.11
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• pp.616-621
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• 2015

Atmospheric pressure plasma is used in the biological and medical fields. Miniaturization and safety are important in the application of apply atmospheric plasma to bio devices. In this study, we made a small, pocket-sized inverter for the discharge of atmospheric plasma. We used pulse power to control the neutral gas temperature at which the, when plasma was discharged. We used direct current of 5 V of bias(voltage). The output voltage is about 1 to 2 kilo volts the frequency is about 80 kilo hertz. We analyzsed the characteristics of the atmospheric plasma using OES(Optical emission spectroscopy) and the Current-Voltage characteristic of pulse power. By calculating of the current voltage characteristics, we were able to determine that, when the duty ratio increased, the power that actually effects the plasma discharge also increased. To apply atmospheric plasma to human organisms, the temperature is the most important factor, we were able to control the temperature by modulating the pulse power duty ratio. This means we can use atmospheric plasma on the human body or in other areas of the medical field.

• Korean Journal of Materials Research
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• v.13 no.4
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• pp.271-278
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• 2003

Conventional backlight for liquid crystal display (LCD) uses mercury which leads to environmental pollution. In this study, characteristics of AC coplanar type mercury-free plasma flat lamp have been studied. Pollution-free Xe-He is adopted as a discharge gas system. Since the Xe gas has a lower efficiency in generating vacuum ultraviolet (VUV) than mercury, the improvement of luminance and luminous efficiency in the Xe gas system is very important. The electrode, dielectric, and phosphor layers constituting lamp are formed on the bottom glass by the screen printing method. The effects of pulse shape, on-time, and pulse frequency on the luminance and luminous efficiency have been examined. For Xe(5%)-He gas, the lamp exhibits higher efficiency with sharper pulse shape, higher peak voltage, and shorter pulse on-time (up to 2 $\mu\textrm{s}$). Higher efficiency and lower consumption of power were obtained at 30 kHz than at 60 kHz. The collision of ion to bottom electrodes is a dominant factor to raise the lamp temperature. Therefore the high voltage and low current discharge system is necessary for reduction of the lamp temperature as well as for enhancement of the luminous efficiency.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.96-97
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• 2012

In nitride and oxide film deposition, sputtered metals react with nitrogen or oxygen gas in a vacuum chamber to form metal nitride or oxide films on a substrate. The physical properties of sputtered films (metals, oxides, and nitrides) are strongly influenced by magnetron plasma density during the deposition process. Typical target power densities on the magnetron during the deposition process are ~ (5-30) W/cm2, which gives a relatively low plasma density. The main challenge in reactive sputtering is the ability to generate a stable, arc free discharge at high plasma densities. Arcs occur due to formation of an insulating layer on the target surface caused by the re-deposition effect. One current method of generating an arc free discharge is to use the commercially available Pinnacle Plus+ Pulsed DC plasma generator manufactured by Advanced Energy Inc. This plasma generator uses a positive voltage pulse between negative pulses to attract electrons and discharge the target surface, thus preventing arc formation. However, this method can only generate low density plasma and therefore cannot allow full control of film properties. Also, after long runs ~ (1-3) hours, depends on duty cycle the stability of the reactive process is reduced due to increased probability of arc formation. Between 1995 and 1999, a new way of magnetron sputtering called HIPIMS (highly ionized pulse impulse magnetron sputtering) was developed. The main idea of this approach is to apply short ${\sim}(50-100){\mu}s$ high power pulses with a target power densities during the pulse between ~ (1-3) kW/cm2. These high power pulses generate high-density magnetron plasma that can significantly improve and control film properties. From the beginning, HIPIMS method has been applied to reactive sputtering processes for deposition of conductive and nonconductive films. However, commercially available HIPIMS plasma generators have not been able to create a stable, arc-free discharge in most reactive magnetron sputtering processes. HIPIMS plasma generators have been successfully used in reactive sputtering of nitrides for hard coating applications and for Al2O3 films. But until now there has been no HIPIMS data presented on reactive sputtering in cluster tools for semiconductors and MEMs applications. In this presentation, a new method of generating an arc free discharge for reactive HIPIMS using the new Cyprium plasma generator from Zpulser LLC will be introduced. Data (or evidence) will be presented showing that arc formation in reactive HIPIMS can be controlled without applying a positive voltage pulse between high power pulses. Arc-free reactive HIPIMS processes for sputtering AlN, TiO2, TiN and Si3N4 on the Applied Materials ENDURA 200 mm cluster tool will be presented. A direct comparison of the properties of films sputtered with the Advanced Energy Pinnacle Plus + plasma generator and the Zpulser Cyprium plasma generator will be presented.

• Journal of Information Display
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• v.2 no.1
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• pp.24-33
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• 2001

The characteristics of the reset and the address discharges of an alternating current Plasma Display Panel (ac PDP) were studied using 2-dimensional numerical discharge cell simulation. We investigated the wall charge variations during the reset discharge adopting ramping reset pulse and the subsequent addressing discharge. The roles of the ramping reset scheme can be divided into two stages, each electrode gathers wall charges during ramping-up of the initial stage and the built-up wall charges are lost during ramping-down of the later stage. Address discharge does not only change the wall charge distributions on the address and the scan electrodes but also on the sustain electrode. The increase in the wall charges on the sustain electrode was observed with the variation of the applied voltage to the sustain electrode during the address period. The increase of the applied voltage to the sustain electrode during the address period is expected to induce the decrease of the sustain voltage during the display period.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.717-720
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• 2012

Various types of dielectric-barrier-discharge (DBD) devices have been developed for diverse applications for the last decade. In this study, a flat non-thermal DBD micro plasma source under atmospheric pressure has been developed. The flat-panel type plasma is generated by bipolar pulse voltages, and driving gas is air. In this study, the plasma source was investigated with intensified charge coupled device (ICCD) images and Optical Emission Spectroscopy (OES). The micro discharges are generated on the crossed electrodes. For theoretical analysis, 2-dimensional fluid simulation was performed. The plasma source can be driven in air, and thus the operation cost is low and the range of application is wide.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.13-21
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• 2001

The discharge characteristics of 3 electrcdes AC surface discharge plasma display were analyzed. For an unstable state of the discharge which appeared at the maximum discharge voltage, it is found that a parbal erase of the wall charge by the second discharge is a cause. Based on the second discharge, new operation margin considering the interrelation between the address discharge and the display discharge was defined and the validity of it was verified by the experiments. It is necessary to decrease the acklress pulse width for high-speed addressing. However, the operation margin of the ackIress pulse decreases as the pulse width of it becomes narrower. If the address pulse width is wider than l[ps], the operation margin of the display discharge is not related to the address pulse width. From the experimental result, image or 8bit 253 gray level was displayed on PDP with the cell structure of the HDTV class by using the high-speed address ADS drive methcd with pulse width of $1[{\mu}s]$ and the brightness of $560[cd/m^2]$ was obtained. ained.