• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.271-274
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• 1999

In this paper, we studied the matrix type Powder AC Electroluminescence using ZnS:Cu,Cl Phosphor. Previously, Powder AC EL was used in Backlighting of LCD. Rescently, organic Thin Film EL was rapidly developed because of high Luminescence and low applied voltage. But Powder AC EL has Superior features that include sheet like flexibility thickness, low weight, self-emission, a wide viewing angle and a fast response time. We tried to change of phosphor thickness and binder mixture rate in order to obtain the good condition of powder AC EL and we obtained the very low breakdown voltage that was just 15V. Till now, we measured the current-voltage(V-I), luminance-voltage(V-L), Luminance-current (L-I), color coordinate (CIE), and phosphor Intensity of variable thickness. In experiment result, the devices has the luminance of 840 cd/$m^2$ and improved color coordinate, x=0.1557, y=0.2145, using a 10kHz drive frequency.

• Transactions on Electrical and Electronic Materials
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• v.17 no.2
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• pp.113-117
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• 2016

Temperature dependent reverse-bias current-voltage (I-V) characteristics in Cu Schottky contacts to oxygen plasma treated n-InP were investigated. For untreated sample, current transport mechanisms at low and high temperatures were explained by thermionic emission (TE) and TE combined with barrier lowering, respectively. For plasma treated sample, experimental I-V data were explained by TE or TE combined with barrier lowering models at low and high temperatures. However, the current transport was explained by a thermionic field emission (TFE) model at intermediate temperatures. From X-ray photoemission spectroscopy (XPS) measurements, phosphorus vacancies (VP) were suggested to be generated after oxygen plasma treatment. V_P possibly involves defects contributing to the current transport at intermediate temperatures. Therefore, minimizing the generation of these defects after oxygen plasma treatment is required to reduce the reverse-bias leakage current.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.12
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• pp.82-90
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• 2011

A novel class AB current subtracter(CS) and its application to Norton amplifier(NA) for low-power current-mode signal processing are designed. The CS is composed of a translinear cell, two current mirrors, and two common-emitter(CB) amplifiers. The principle of the current subtraction is that the difference of two input current applied translinear cell get from the current mirror, and then the current amplify through CB amplifier with ${\beta}$ times. The NA is consisted of the CS and wideband voltage buffer. The simulation results show that the CS has current input impedance of $20{\Omega}$, current gain of 50, and current input range of $i_{IN1}$ > $i_{IN2}{\geq}4I_B$. The NA has unit gain frequency of 312 MHz, transresistance of 130 dB, and power dissipation of 4mW at ${\pm}2.5V$ supply voltage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.751-753
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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. The CuPc FET device was made a top-contact type and the substrate temperature was room temperature. The source and drain electrodes were used an Au and Al materials. The CuPc thickness was 40nm. and the channel length was $50{\mu}m$, channel width was 3mm. We observed a typical current-voltage (I-V) characteristics in CuPc FET with different electrode materials.

• Journal of Advanced Marine Engineering and Technology
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• v.32 no.8
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• pp.1263-1268
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• 2008

In this paper, the low noise power amplifier for GaAs FET ATF-10136 is designed and fabricated with active bias circuit and self bias circuit. To supply most suitable voltage and current, active bias circuit is designed. Active biasing offers the advantage that variations in the pinch-off voltage($V_p$) and saturated drain current($I_{DSS}$) will not necessitate a change in either the source or drain resistor value for a given bias condition. The active bias network automatically sets a gate-source voltage($V_{gs}$) for the desired drain voltage and drain current. Using resistive decoupling circuits, a signal at low frequency is dissipated by a resistor. This design method increases the stability of the LNA, suitable for input stage matching and gate source bias. The LNA is fabricated on FR-4 substrate with active and self bias circuit, and integrated in aluminum housing. As a results, the characteristics of the active and self bias circuit LNA implemented more than 13 dB and 14 dB in gain, lower than 1 dB and 1.1 dB in noise figure, 1.7 and 1.8 input VSWR at normalized frequency $1.4{\sim}1.6$, respectively.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1675-1677
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• 1997

In this paper we study the voltage-current characteristics inside the wire-plate precipitators by numerically solving the Poisson's equation and current continuity equation. The effects of a wire size, wire-wire spacing, wire-plate spacing and effective mobility have been considered.

• Korean Journal of Materials Research
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• v.26 no.8
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• pp.412-416
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• 2016

The electrical properties of Au/n-type Ge Schottky contacts with different contact areas were investigated using current-voltage (I-V) measurements. Analyses of the reverse bias current characteristics showed that the Poole-Frenkel effect became strong with decreasing contact area. The contribution of the perimeter current density to the total current density was found to increase with increasing reverse bias voltage. Fitting of the forward bias I-V characteristics by considering various transport models revealed that the tunneling current is dominant in the low forward bias region. The contributions of both the thermionic emission (TE) and the generation-recombination (GR) currents to the total current were similar regardless of the contact area, indicating that these currents mainly flow through the bulk region. In contrast, the contribution of the tunneling current to the total current increased with decreasing contact area. The largest $E_{00}$ value (related to tunneling probability) for the smallest contact area was associated with higher tunneling effect.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.41-44
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• 2003

We propose portable equipment that monitors current and voltage of high-potential power transmission lines. In the equipment, a current and voltage sensor are attached to an insulator that supports a power transmission line: A clamped to the power line and the detected current signal is transmitted to the ground station by a wireless optical link using transmission line is detected by a high resistance element, zinc oxide (ZnO). That acts as a potential divider between the power line and ground. We make an experimental device for 66kV power line and demonstrate that it can monitor currents proposed equipment is small-sized, light, and inexpensive in comparison with the conventional CT (current transformer) and PT (potential transformer) since it does not require high potential insulators and magnetic cores, further, the equipment is easily installed owing to its small size and its simple structure.

• Journal of the Korean Vacuum Society
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• v.3 no.1
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• pp.71-76
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• 1994

The electrical characteristics of the capacitor dielectric films of amorphous silicon-nit-ride-oxide(ANO) structures are compared with the capacitor dielectric films of oxide-nitride-oxide (ONO) structrues The electrical characteristics of ONO and ANO films were evaluated by high frequency(1 MHz) C-V high frequency C-V after constant voltage stree I-V TDDB and refresh time measurements. ANO films shows good electrical characteristics such as higher total charge to breakdown storage capacitance and longer refresh time than ONO films. Also it makes little difference that leakage current and flat band voltage shyift(ΔVfb)of ANO ana ONO films.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.3
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• pp.135-140
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• 2018

Atomically thin $MoS_2$ single crystals have a two-dimensional structure and exhibit semiconductor properties, and have therefore recently been utilized in electronic devices and circuits. In this study, we have fabricated a field effect transistor (FET), using a CVD-grown, 3 nm-thin, $MoS_2$ single-crystal as a transistor channel after transfer onto a $SiO_2/Si$ substrate. The $MoS_2$ FETs displayed n-channel characteristics with an electron mobility of $0.05cm^2/V-sec$, and a current on/off ratio of $I_{ON}/I_{OFF}{\simeq}5{\times}10^4$. Application of bottom-gate voltage stresses, however, increased the interface charges on $MoS_2/SiO_2$, incurred the threshold voltage change, and degraded the device performance in further measurements. Exposure of the channel to UV radiation further degraded the device properties.