• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.137-138
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.145-146
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• 2008

• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.60-63
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• 2003

For the increase the charge stability of teflon electrets for used at uncomfortable industrial circumstances with high temperature or humidity, We made an investigation into double layer effect of teflon electrets. Teflon AF film was spincoated on FEP film and then the charge storage property of AF/FEP dual film was investigated to be compared with FEP film. It was found that the AF/FEP dual film has higher surface potential than FEP film on the repeated charging and annealing process. It seems that AF/FEP dual film has higher thermal stability than FEP film through TSC measurement. If the investigations of the double layer effect of Teflon film carried out more closely with it's molecular structures and surface conditions, it may be effectively improved the stability of charge storage.

• 전기의세계
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• v.29 no.8
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• pp.511-518
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• 1980

The thermostimulated discharge currents of low-density polyethylene electrets were measured versus the principal experimental variables. Several electrode types were used for the charging and discharging procedures. The results led to know the experimental conditions for the heterocharge and homocharge accumulating and decreasing. The electronic structure parameters of polyethylene such as trap level, density of traps, hopping length, mobility, trap time constants were deduced. A method for evaluating the local electric field inside the electret is proposed.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.31-32
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• 2010

In our previous reports [1-3], electron transport for the switching and memory devices using alkyl thiol-tethered Ru-terpyridine complex compounds with metal-insulator-metal crossbar structure has been presented. On the other hand, among organic memory devices, a memory based on the OFET is attractive because of its nondestructive readout and single transistor applications. Several attempts at nonvolatile organic memories involve electrets, which are chargeable dielectrics. However, these devices still do not sufficiently satisfy the criteria demanded in order to compete with other types of memory devices, and the electrets are generally limited to polymer materials. Until now, there is no report on nonvolatile organic electrets using nano-interfaced organic monomer layer as a dielectric material even though the use of organic monomer materials become important for the development of molecularly interfaced memory and logic elements. Furthermore, to increase a retention time for the nonvolatile organic memory device as well as to understand an intrinsic memory property, a molecular design of the organic materials is also getting important issue. In this presentation, we report on the OFET memory device built on a silicon wafer and based on films of pentacene and a SiO2 gate insulator that are separated by organic molecules which act as a gate dielectric. We proposed push-pull organic molecules (PPOM) containing triarylamine asan electron donating group (EDG), thiophene as a spacer, and malononitrile as an electron withdrawing group (EWG). The PPOM were designed to control charge transport by differences of the dihedral angles induced by a steric hindrance effect of side chainswithin the molecules. Therefore, we expect that these PPOM with potential energy barrier can save the charges which are transported to the nano-interface between the semiconductor and organic molecules used as the dielectrics. Finally, we also expect that the charges can be contributed to the memory capacity of the memory OFET device.[4]

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.11a
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• pp.147-148
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.09a
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• pp.47-51
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• 2001

The electrical degradation phenomena of epoxy composites to be used as a molding material for transformers were studied. The electrets were first manufactured by applying high voltages to five kinds of specimens given a mixing rate, and then TSC(Thermally Stimulated Current) values at the temperature range of $-160\sim200[^{\circ}C]$ were measured from a series of experiments. The behaviour of carrier and its origin in epoxy composites were examined, respectively, And various effects of electrical degradation on epoxy composites were also discussed in this study.

• Electrical & Electronic Materials
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• v.6 no.4
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• pp.302-310
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• 1993

일렉트렛트이란 자석과 대칭한 호칭으로 영구전기분극을 갖는 절연체를 말한다. 일랙트렛트는 1919년 강구에 의해 창제되었는데 이것은 왁스와 송지를 등량으로 혼합하여 만든것이었으나 최근에는 테프론이나 마이러, 폴리프로필렌등의 고분자 필름으로 만들게 되었다. 많은 고분자 재료는 절연성이 좋고 가공 성형도 용이하기 때문에 일랙트렛트로 하기에 편리하다. 그중에서도 합성고분자 필름에 의한 일랙트렛트는 마이크로폰이나 카트리지 등의 음향소자에 쓰이는 외에 정전모우터, 릴레이스위치, 에어필터나 의용재료에 널리 이용될 가능성이 나오고 있다.

• 전기의세계
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• v.30 no.8
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• pp.517-524
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• 1981

Thermally stimulated currents have been obtained from five kinds of polymer electrets. The peak current (I$_{m}$) and the peak temperature (T$_{m}$) of the TSC, particularly at PET thermoelectret, were found to depend on the forming field and the forming temperature. From these experimental results, the TSC spectra can be easily explained by the consideration of the disorientation of dipoles related with glass transition temperature. The obtained results can suggest that the forming field and the forming temperature plays an essential role for charge stability in PET thermoelectrets.ets.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1105-1107
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• 1995

In order to examine closely the corona degradation of epoxy composites, the corona electrets which are formed by appling high voltages, 300[kV/cm], to epoxy composites are experimented to measure TSC(thermally stimulated currents) at the temperature range of $-160{\sim}200[^{\circ}C]$ and to investigate the various aspects due to corona degradation in this study.