• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.223-226
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• 1998

In this paper, we have investigated how morphology and electrical properties in Polyphenylene sulfide(PPS) are changed by uniaxial elongation. XRD pattern shows that interplanar distance and crystallinities are decreased by increasing elongation ratio. Electrical conduction mechanism of PPS is explained as schottky emission from analysis of electrical current. The electrical current is decreased by increasing elongation ratio. The conductivity is changed remarkably above the glass transition temperature around $(82^{\circ}C)$. The band gap of PPS is evaluated as 3.9-4(eV) from the results of photoconductivity. Increarnent of elongation ratio gives us some information about deep trap formation from photocurrent.

• 한국전기전자재료학회논문지
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• 제27권7호
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• pp.428-432
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• 2014

The Hall factor in a two-dimensional device with indirect conduction valleys is calculated for several growth on various strain conditions. In the [001] or [111] growth direction, the two-dimensional constant energy surfaces of occupied valleys are shown to be isotropically distributed. However, in the [110] growth direction, the distribution of occupied valleys on the plane is not isotropic. This fact is the reason for the anisotropic Hall factor on the sample plane.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.176-183
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• 1995

The present work is concerned with the switching conduction characteristics of PI LB films in metal insulator metal sandwiches. By applying various DC voltage bias to MIM junctions, conduction characteristics of junctions can be changed between the high-voltage low-current(off) condition, the low-voltage high-current (on) condition and the medium(mid) condition. Switching conduction characteristics can be also observed in MIM junctions employing some aromatic compounds as insulators. Switching conduction characteristics is assumed to be owing to the existence of aromatic rings, space charge in films, impurities on metal-insulator interface, and difference in work functions of base and top electrodes metal. To study the conduction process of on, off, and mid conductions, we measured I-V, d$^{2}$V/d I$^{2}$-V characteristics of junctions with several different top electrodes under various temperatures. Small conductance changes of junctions can be measured by observing the second derivative, d$^{2}$V/dI$^{2}$, of I-V curve. A dynamical technique is used to get the second derivatives. That is, a finite modulation of the current is applied to the junctions and the second harmonic of the voltage is detected.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1990년도 추계학술대회 논문집
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• pp.74-77
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• 1990

In this paper, we study the electrical conduction mechanism in Langmuir-Boldgett(LB) ultra thin films. The LB device has a metal/Lb films/metal sandwich structure, where metal is electrode. In our experiments, the temperature does not depend on the current at below 0$^{\circ}C$. This phenomena show that the electrical conduction current is a tunnel current inherent to LB ultra thin films.

• E2M - 전기 전자와 첨단 소재
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• 제10권5호
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• pp.453-460
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• 1997

In order to investigate the electrical conduction properties of polyethylene thin film for power cable with manufacturing methods, the thickness of specimen was the 30, 100[${\mu}{\textrm}{m}$] of LDPE and 200[${\mu}{\textrm}{m}$] of XLPE were manufactured. The experimental condition for conduction properties was measured until the breakdown occurs at temperature ranges from 30 to 110[$^{\circ}C$] and the electric field from 1$\times$10$^3$to 5$\times$10$^{6}$ [V/cm]. As for increase of temperature, the current density of LDPE was increased with constant ratio in low field, but changes with exponential function in high electric field. The tunnel current of pre-breakdown region is shifted toward low field as much as thermal excitation energy. At low electric field, the XLPE showed dominant electrical conduction properties by thermal excitation, and transformation of the electron was resisted by the crystal at high electric field.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.219-222
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• 1998

The space charge and conduction characteristics of chemically modified vinylpyridine (VP) grafted low density polyethylene (LDPE) was investigated. VP grafted LDPE was analyzed by elemental analysis (EA) to confirm the grafting reaction. Homocharge was developed in VP grafted LDPE at low graft ratios and changed to heterocharge with increasing the content of VP. In conduction experiment, current densities of VP grafted LDPE were lower than that of LDPE and VP grafted LDPEs showed almost the same conduction characteristics as vinylpyridine graft ratio increased

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.108-111
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• 1988

In this study, the electrical conduction properties of plasma-polymerized (MMA+Styrene) thin film have been investigated. The measurements of transient conduction currents were carried out in the temperature of 50 to 150$^{\circ}C$ at electric field of 10$^4$to 10$\^$6/V/cm. The electric field-current density characteristic curves were divided into three regions-ohmic region, child region, sudden-increasing region. It is shown that the conduction mechanism of this thin film is in good agreement with SCLC(space charge limited current) model by applying the high field conduction theories.

• 전자공학회논문지SC
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• 제43권5호
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• pp.60-67
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• 2006

우주 비행체 전자장비의 신뢰도를 예측하고 최적화하기 위해 탑재장치 내 부품의 온도 예측이 필수적으로 요구된다. 본 논문에서는 전자장비 부품의 온도 예측방법에 관해 기술하고 있다. 본 예측 방법은 PCB 기판의 열전도도를 등방성모델로 설정하여 등가 열전도도를 계산하고 열력 모델을 이용하여 열 저항 행렬을 생성하였으며, 중첩의 원리를 이용하여 각 부품들의 온도를 예측하였다. 또한 본 논문의 온도 예측방법을 이용하여 전장품 소자의 열해석 결과와 상용 프로그램을 이용한 온도 계산 결과를 비교 분석하였다.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.220-226
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• 2002

Amorphous $Sb_{2-x}Bi_xTe_3$ (x = 0.0, 0.5 and 1.0) thin films were prepared by vacuum evaporation. The resistivity of 7he films decreases from 1.4{\times}10^{-2}$ to $8.84{\times}10^{-5}\Omega cm$ and the type of conductivity changes from p to n with the increase of the x value of the films. D.C. conduction studies on these films ate performed at various electric fields in the temperature range of 303-403 K. At low electric fields, two types of conduction mechanisms, i.e. the variable range hopping and the phonon assisted hopping are found to be responsible for the conduction, depending upon the temperature. The activation energy decreases from 0.082 to 0.076 eV in the temperature range of 303-363 K and from 0.47-0.456 eV in the second range of 363-403 K, indicating the shift of the Fermi level towards the conduction band edge and hence the change of the conduction from P to n type with the increase of the Bi concentration. Poole-Frankel emission dominates at high fields. The shape of the potential well of the localized centre is deduced and the mean free path of the charge carriers is also calculated.

• 한국전기전자재료학회논문지
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• 제20권2호
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• pp.135-141
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• 2007

The conduction-cooled HTS SMES is operated in cryogenic and high vacuum condition. Thus, Insulation design at cryogenic temperature and high vacuum is a key and an important element that should be established to accomplish miniaturization that is a big advantage of HTS SMES. However, the behaviors of insulators for cryogenic conditions in vacuum are virtually unknown. Therefore, we need active research and development of insulation concerning application of the conduction-cooled HTS SMES. Therefore, in this study, we experimented about insulation characteristic high vacuum and cryogenic similar to driving condition of SMES system. Also, investigated about insulation characteristic of suitable some materials to insulator for conduction-cooled HTS SMES. As this results, we possessed basis data for insulation materials selection and insulation design for development of 600 kJ class conduction-cooled HTS SMES.