• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권3호
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• pp.114-119
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• 2005

We investigated compatibilizing effects of electrical properties such as charge distributions and electrical breakdown in blends of low density polyethylene (LDPE) / polystyrene (PS) with poly [styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS), the triblock copolymer. The blends with $70\;wt\%$ of LDPE and $30\;wt\%$ of PS were prepared through a melt blending in a batch type kneader at a temperature of $220^{\circ}C$ when the SEBS content increased up to $10\;wt\%$. Scanning electron microscopy (SEM) was investigated for observation of morphology of LDPE / PS blends increasing SEBS contents. The morphological observation showed that addition of SEBS results in the domain size reduction of the dispersed PS phase and a better interfacial adhesion between LDPE and PS phases. Measurements of space charge distributions for blends was carried out with pulsed electroacoustic (PEA) method. It was possible to observe that the amount of charge storage in the LDPE / PS blends decreased wiか increasing of SEBS content. The location of SEBS at a domain interface enables charges to move from one phase to the other via domain interface and results in a indicative decrease in the amount of space charge for the LDPE / PS blends with SEBS. Electrical breakdown strength of these blends was observed. It was found that the maximum breakdown strength of the blend was 51.55 kV/mm. These results were better than 38.38 kV/mm of LDPE used electrical insulator for cables and were caused by crystalinity of blends. Because the crystalinity of blends were lower than LDPE, electrical breakdown strength of LDPE / PS blends is higher than that of LDPE. We evaluated the possibility of these blends for insulating material substituted LDPE.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.101-101
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• 2000

MSC(Multispectral Camera), which will be a unique payload on KOMPSAT-II, is designed to collect panchromatic and multi-spectral imagery with a ground sample distance of 1m and a swath width of 15km at 685km altitude in sun-synchronous orbit. The instrument is designed to have an orbit operation duty cycle of 20% over the mission life time of 3 years. MSC electronics consists of three main subsystems; PMU(Payload Management Unit), CEU(Camera Electronics Unit) and PDTS(Payload Data Transmission Subsystem). PMU performs all the interface between spacecraft and MSC, and manages all the other subsystems by sending commands to them and receiving telemetry from them with software protocol through RS-422 interface. CEU controls FPA(Focal Plane Assembly) which contains TDI(Timc Delay Integration) CCD(Charge Coupled Device) and its clock drivers. PMU provides a Master Clock to synchronize panchromatic and multispectral camera. PDTS performs compression, storage and encryption of image data and transmits them to the ground station through x-band.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.157-158
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• 2007

Effects of post-metallization anneal (PMA) on interface trap characteristics of Si-$SiO_2$ are studied. The conventional PMA method utilizes forming gas anneal, where 10% hydrogen in nitrogen atmosphere is used. A new PMA method utilizes hydrogen rich PECVD- silicon nitride $(SiN_x)$ film as a hydrogen diffusion source and a out-diffusion blocking layer. It can be shown through charge pumping current measurement that the new PMA is indeed effective to decrease Si-$SiO_2$ interface trap density.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제25회 추계학술대회논문집
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• pp.184-187
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• 2005

SUS 304 발열선(직경 2.3mil)과 $Zr-KClO_4$ 기폭화약을 사용한 전기식 착화기에 대한 열특성을 시험하고 Fitted Wire Model로 분석한 결과, 약 $300^{\circ}C$ 부근에서 기폭화약과 관련된 열특성 파라미터가 급격하게 변화되었다. 이 현상은 기폭화약에 사용된 $KClO_4$의 상변화로 인한 흡열과 발열선과 기폭화약 계면의 물리적 변화로 발생된 것으로 판단되며, 결과로 열특성 시험으로 구한 파라미터가 유용한 온도 범위를 제시하였다.

• 한국전기전자재료학회논문지
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• 제30권10호
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• pp.665-671
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• 2017

Herein, we report the fabrication of low-voltage N-type organic field-effect transistors by using high capacitance fluorinated polymer gate dielectrics such as P(VDF-TrFE), P(VDF-TrFE-CTFE), and P(VDF-TrFE-CFE). Electron-withdrawing functional groups in PVDF-based polymers typically cause the depletion of negative charge carriers and a high contact resistance in N-channel organic semiconductors. Therefore, we incorporated intermediate layers of a low-k polymerto prevent the formation of a direct interface between PVDF-based gate insulators and the semiconducting active layer. Consequently, electron depletion is inhibited, and the high charge resistance between the semiconductor and source/drain electrodes is remarkably improved by the in corporation of solution-processed charge injection layers.

• Transactions on Electrical and Electronic Materials
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• 제17권6호
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• pp.380-382
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• 2016

The mechanism for instability under PBS (positive bias stress) in amorphous SIZO (Si-In-Zn-O) thin-film transistors was investigated by analyzing the charge trapping mechanism. It was found that the bulk traps in the SIZO channel layer and the channel/dielectric interfacial traps are not created during the PBS duration. This result suggests that charge trapping in gate dielectric, and/or in oxide semiconductor bulk, and/or at the channel/dielectric interface is a more dominant mechanism than the creation of defects in the SIZO-TFTs.

• 한국결정성장학회지
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• 제11권1호
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• pp.38-42
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• 2001

Electric and dielectric(Ba,Sr)$TiO_3$[BST] thin films for emtal-Insulator-Semiconductor(MIS) capacitors have been studied. BST thin films wre deposted on p-Si(100) substrates bythe RF magnetron sputtering with tempratue range of 500~$600^{\circ}C$. The dielectric properties of MIS capacitors consisting of Al/BST/$SiO_2$/Si sandwich structure were evaluated ot redcue the leakage current density. The charge state densities of the MIS capacitors were determined by high frequency (1 MHz) C-V measurement. In order to reduce the leakage current in MIS capacitor, high quality $SiO_2$ layer was deposited on bare p-Si substrate. Depending on the oxygen pressure and substrate temperature both positive and negative polarities of effective oxide charge in the MIS capacitors were evaluated. It is considered that the density of electronic states, generated at the BST/$SiO_2$/p-Si interface due to the asymmetric structure within BST/$SiO_2$/Si structure, and the oxygen vacancy content has influence on the behavior of oxide charge.

• Electronic Materials Letters
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• 제14권6호
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• pp.657-668
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• 2018

Organic-inorganic hybrid lead halide perovskites have been extensively investigated for various optoelectronic applications. Particularly, owing to their ability to form highly crystalline and homogeneous films utilizing low-temperature solution processes (< $150^{\circ}C$), perovskites have become promising photoactive materials for realizing high-performance flexible solar cells. However, the current use of mesoporous $TiO_2$ scaff olds, which require high-temperature sintering processes (> $400^{\circ}C$), has limited the fabrication of perovskite solar cells on flexible substrates. Therefore, the development of a low-temperature processable charge-transporting layer has emerged as an urgent task for achieving flexible perovskite solar cells. This review summarizes the recent progress in low-temperature processable electron- and hole-transporting layer materials, which contribute to improved device performance in flexible perovskite solar cells.

• 반도체디스플레이기술학회지
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• 제16권3호
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• pp.59-64
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• 2017

As the demand on displays increases, new thin-film transistors such as metal oxide transistor are continuously being invented. When designing a circuit consisting of such new transistors, a new transistor model based on proper charge transport mechanisms is needed for each of them. In this paper, a modeling framework which enables to choose charge transport mechanisms that are limited to certain operation regions and assemble them into a transistor model instead of making an integrated transistor model dedicated to each transistor. The framework consists of a graphic user interface to choose charge transport models and a current calculation part, which is also implemented in AIM-SPICE for circuit simulation.

• 한국전기전자재료학회논문지
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• 제37권4호
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• pp.451-456
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• 2024

Organic photovoltaic (OPV) devices have attracted attention due to their high efficiency and simple manufacturing process. Applying an overlayer to OPV devices is one way to improve their performance because it can improve charge extraction and suppress vertical phase separation. In addition, dichloromethane (DCM) was used as an orthogonal solvent to minimize the effect on other layers. However, an coating problems due to the use of DCM were found, which affects surface morphology as rough or peeling. Additional research efforts are needed to solve these problems, and optimal results are expected to be obtained by utilizing various buffer layers or selective organic solvents.