• 제목/요약/키워드: plastic substrate

검색결과 337건 처리시간 0.03초

Long-term Air Stability of Small Molecules passivated-Graphene Field Effect Transistors

  • Shin, Dong Heon;Kim, Yoon Jeong;Kim, Sang Jin;Moon, Byung Joon;Oh, Yelin;Ahn, Seokhoon;Bae, Sukang
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.237.1-237.1
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    • 2016
  • Electrical properties of graphene-based field effect transistors (G-FETs) can be degraded in ambient conditions owing to physisorbed oxygen or water molecules on the graphene surface. Passivation technique is one of a fascinating strategy for fabrication of G-FETs, which allows to sustain electrical properties of graphene in the long term without disrupting its inherent properties: transparency, flexibility and thinness. Ironically, despite its importance in producing high performance graphene devices, this method has been much less studied compared to patterning or device fabrication processes. Here we report a novel surface passivation method by using atomically thin self-assembled alkane layers such as C18- NH2, C18-Br and C36 to prevent unintentional doping effects that can suppress the degradation of electrical properties. In each passivated device, we observe a shift in charge neutral point to near zero gate voltage and it maintains the device performance for 1 year. In addition, the fabricated PG-FETs on a plastic substrate with ion-gel gate dielectrics exhibit not only mechanical flexibility but also long-term stability in ambient conditions. Therefore, we believe that these highly transparent and ultra-thin passivation layers can become a promising candidate in a wide range of graphene based electronic applications.

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나노인덴테이션 시험과 유한요소해석을 이용한 자동차 도금 강판의 도금층 체적 거동결정 및 성형해석 적용 (Identification of the Bulk Behavior of Coatings by Nanoindentation Test and FE-Simulation and Its Application to Forming Analysis of the Coated Steel Sheet)

  • 이정민;이경수;고대철;김병민
    • 대한기계학회논문집A
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    • 제30권11호
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    • pp.1425-1432
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    • 2006
  • Coating layers on a coated sheet steel frequently affect distributions of strain rate of sheets and deteriorate the frictional characteristics between sheets and tools in sheet metal forming. Thus, it is important to identify the deformation behavior of these coatings to ensure the success of the sheet forming operation. In this study, the technique using nano-indentation test, FE-simulation and Artificial Neural Network(ANN) were proposed to determine the power law stress-strain behavior of coating layer and the power law behavior of extracted coating layers was examined using FE-simulation of drawing and nano-indentation process. Also, deep drawing test was performed to estimate the formability and frictional characteristic of coated sheet, which was calculated using the linear relationship between drawing force and blank holding force obtained from the deep drawing test. FE-simulations of the drawing process were respectively carried out for single-behavior FE-model having one stress-strain behavior and for layer-behavior FE-model which consist of coating and substrate separately. The results of simulations showed that layer-behavior model can predict drawing forces with more accuracy in comparison with single-behavior model. Also, mean friction coefficients used in FE-simulation signify the value that can occur maximum drawing force in a drawing test.

${Al_2}}O_3}-TiO_2$ 플라즈마 코팅된 유리의 입자충격에 의한 손상기구 (Damage mechanism of particle impact in a ${Al_2}}O_3}-TiO_2$plasma coated soda-lime glass)

  • 서창민;이문환;홍대영
    • 대한기계학회논문집A
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    • 제22권3호
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    • pp.529-539
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    • 1998
  • A quantitative study of impact damage of ${Al_2}}O_3}-TiO_2$ plasma coated soda-lime glasses was carried out and compared with that of the uncoated smooth glass specimen. The shape of cracks by the impact of steel ball was observed by stereo-microscope and the decrease of the bending strength due to the impact of steel ball was measured through the 4-point bending test. At the low velocity, cone cracks were occurred. As the impact velocity increases, initial lateral cracks were propagated on the slanting surface of a cone crack, and radial cracks were generated at the crushed site. When the impact velocity of steel ball exceeds the critical velocity, the contact site of specimen was crushed due to plastic deformation and then radial and lateral cracks were largely grown. Crack length of coated specimens was smaller than that of uncoated smooth specimen due to the effect of coating layer on the substrate surface. According to impact velocity, the bending strength of coated specimens had no significant difference, compared with that of the uncoated smooth specimen. But this represents that the bending strength of coated specimens was increased, considering the effect of sand blasting damage which was performed to increase the adhesion force of coating layer.

시설재배조건에서 서양민들레의 생육 및 생리활성물질 변이 연구 (Change in Plant Growth and Physiologically-Active Compounds Content of Taraxacum officinale under Plastic House Condition)

  • 천상욱;박정숙
    • 한국작물학회지
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    • 제57권4호
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    • pp.449-455
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    • 2012
  • 서양민들레의 시설생산을 위해 배지조성 및 차광정도를 달리한 환경조건에 대한 생육특성과 그에 따른 생리활성 변이를 검토하고자 온실과 실험실 시험을 수행하였다. 서양민들레 시설생산을 위한 적정한 배지조합은 coco peat와 perlite를 각각 70 : 30과 50 : 50으로 혼합한 배지가 coco peat와 perlite 각각의 단독배지보다 생육 및 수량에 있어서 유의적으로 높게 나타났다(p<0.05). 차광정도에 따른 서양민들레의 초장, 근장, 엽수, 근직경, 엽면적, 엽록소 함량 및 생체중은 무차광이 50%와 70%차광보다 유의적으로 높게 나타났다(p<0.05). 총 페놀 함량과 총 플라보노이드 함량은 지하부보다는 지상부에서 높게 나타났다. 총 페놀 함량은 무차광에서 차광보다 높게 검출되었고, 총 플라보노이드 함량은 50%차광에서 가장 높았고 그 다음이 무차광과 70%차광 순으로 높았다. 한편, DPPH 라디컬 소거능과 아질산염 측정을 통한 항산화성은 추출물 농도가 증가할수록 높은 활성을 보였고 지하부보다는 지상부에서, 차광보다는 무차광에서 높은 활성을 보였다.

담자균이 배양된 곡물의 유리당 조성 변화 (Comparison of Free Sugar Content in Grains Fermented with Mycelia of the Basidiomycetes)

  • 정인창;하효철;곽희진
    • 한국관광식음료학회지:관광식음료경영연구
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    • 제13권1호
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    • pp.69-80
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    • 2002
  • 약용버섯의 균사체(Ganoderma lucidum 7094, Fomitella fraxinea 81003, Phellinus igniarius 26005)를 곡류와 같은 고체재료에 배양하고 발효된 곡류의 유리당 조성 변화를 관찰함으로써 기능성식품 개발의 가능성을 검토하였다. 담자균사체의 대량배양 조건 실험을 실시한 결과, 냉침에 의해 최대수화에 도달한 곡물을 배양용기에 담고, 액체배양 후 균질화한 담자균사체를 곡물에 접종함으로써 접종초기 짧은 시간에 균사가 완전히 활착되도록 할 수 있었다. 또한 균사 배양중기에 멸균 증류수를 첨가함으로써 균사의 활력을 유지시킬수 있었다. 담자균사체는 종류에 따라 유리당 총량 및 구성비에 있어서 큰 차이를 나타내었다. 또한 담자균사체가 배양된 곡물의 유리당 함량을 측정한 결과, 유리당 총량 및 대부분의 유리당 함량이 곡물 자체에서 보다 증가하였으며, 담자균과 곡물배지의 종류에 따라 당의 이용성에 큰 차이를 나타내었다.

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Full Color Top Emission AMOLED Displays on Flexible Metal Foil

  • Hack, Michael;Hewitt, Richard;Urbanik, Ken;Chwang, Anna;Brown, Julie J.;Lu, Jeng Ping;Shih, Chinwen;Ho, Jackson;Street, Bob;Ramos, Teresa;Rutherford, Nicole;Tognoni, Keith;Anderson, Bob;Huffman, Dave
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.305-308
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    • 2006
  • Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. For portable applications flexible (or conformable) and rugged displays will be the future. In this paper we outline our progress towards developing such a low power consumption active-matrix flexible OLED $(FOLED^{TM})$ display. We demonstrate full color 100 ppi QVGA active matrix OLED displays on flexible stainless steel substrates. Our work in this area is focused on integrating three critical enabling technologies. The first technology component is based on UDC's high efficiency long-lived phosphorescent OLED $(PHOLED^{TM})$ device technology, which has now been commercially demonstrated as meeting the low power consumption performance requirements for mobile display applications. Secondly, is the development of flexible active-matrix backplanes, and for this our team are employing PARC's Excimer Laser Annealed (ELA) poly-Si TFTs formed on metal foil substrates as this approach represents an attractive alternative to fabricating poly-Si TFTs on plastic for the realization of first generation flexible active matrix OLED displays. Unlike most plastics, metal foil substrates can withstand a large thermal load and do not require a moisture and oxygen permeation barrier. Thirdly, the key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing, and in this device we employ a multilayer thin film Barix encapsulation technology in collaboration with Vitex systems. Drive electronics and mechanical packaging are provided by L3 Displays.

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유기EL의 수명향상을 위한 혼합무기박막의 투습율 및 투산소율 특성 연구 (Study on Water Vapor and Oxygen Transmission Rates in Inorganic Composite Films to improvement life-time of OLEDs)

  • 김영민;이주원;김종무;박정수;성만영;장진;주병권;김재경
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.189-192
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    • 2004
  • To improvement life-time of the organic light emitting diodes(OLEDs). We investigate the inorganic composite film based on MgO and $SiO_2$ to protect from the moisture and oxygen. The inorganic composite films are added the base materials to the co-operate materials using the mixed process and it is deposited on plastic substrate by e-beam evaporator. In order to analyze as kinds of inorganic materials, Water Vapor method of Transmission Rate (WVTR) and Oxygen Transmission Rate (OTR) are measured by Permatran equipment(MOCON Corp.). For comparison. an MgD- and $SiO_2$-based composite film has lower values of WVTR and OTR than inorganic composite/compound films of ones. The results obtained here shows that this film is suitable for passivation layer to extend the life-time of OLEDs.

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저온 공정 PVP게이트 절연체를 이용한 고성능 플렉서블 유기박막 트랜지스터의 계면처리 효과 (Interface Treatment Effect of High Performance Flexible Organic Thin Film Transistor (OTFT) Using PVP Gate Dielectric in Low Temperature)

  • 윤호진;백규하;신홍식;이가원;이희덕;도이미
    • 한국전기전자재료학회논문지
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    • 제24권1호
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    • pp.12-16
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    • 2011
  • In this study, we fabricated the flexible pentacene TFTs with the polymer gate dielectric and contact printing method by using the silver nano particle ink as a source/drain material on plastic substrate. In this experiment, to lower the cross-linking temperature of the PVP gate dielectric, UV-Ozone treatment has been used and the process temperature is lowered to $90^{\circ}C$ and the surface is optimized by various treatment to improve device characteristics. We tried various surface treatments; $O_2$ Plasma, hexamethyl-disilazane (HMDS) and octadecyltrichlorosilane (OTS) treatment methods of gate dielectric/semiconductor interface, which reduces trap states such as -OH group and grain boundary in order to improve the OTFTs properties. The optimized OTFT shows the device performance with field effect mobility, on/off current ratio, and the sub-threshold slope were extracted as $0.63cm^2 V^{-1}s^{-1}$, $1.7{\times}10^{-6}$, and of 0.75 V/decade, respectively.

다양한 플라스틱 기판위에 $(SiO_2)_3(ZnO)_7$ 보호층을 갖는 투명 전도성 박막들의 특성 향상 (Enhanced characteristics of TCO films with $(SiO_2)_3(ZnO)_7$ gas barrier layer on various plastic substrates)

  • 권오정;김동영;유성원;손선영;홍우표;김화민;홍재석
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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    • pp.283-284
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    • 2008
  • Electrical and optical characteristics of indium tin oxide (ITO) and indium zinc oxide (IZO) films without and with $(SiO_2)_3(ZnO)_7$ at.% (SZO) film deposited on poly(ethylene naphthalate) (PEN) and poly(ethylene terephthalate (PET) substrates as a gas barrier layer for flexible display were studied. The ITO and IZO films with SZO gas barrier layer showed the improved properties which were both the high transmittance of average 80% in the visible light range and the decreased sheet resistance as compared to those of ITO and IZO films without SZO layer. Particularly, the PEN substrate with only SZO gas barrier layer had a low water vapor transmission rate (WVTR) of $\sim10^{-3}g/m^2$/day. Thus, we suggest that the SZO film with protection ability against the water vapor permeation can be applied to gas barrier layer for flexible display.

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RF Magnetron Sputtering으로 증착된 ZnO의 증착 특성과 이를 이용한 Thin Film Transistor특성 (Thin Film Transistor Characteristics with ZnO Channel Grown by RF Magnetron Sputtering)

  • 김영웅;최덕균
    • 마이크로전자및패키징학회지
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    • 제14권3호
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    • pp.15-20
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    • 2007
  • 플라스틱 기판에 적용이 가능한 최대 공정온도 $270^{\circ}C$ 이하에서 ZnO-TFT 소자를 제작하였다. ZnO-TFT 소자는 bottom gate 구조로 제작되었으며, ICP-CVD로 형성된 $SiO_2$ 산화물 게이트 공정을 제외하고는 모든 박막증착 공정은 RF-magnetron sputtering process를 이용하였다. ZnO 박막은 Ar과 $O_2$ gas 유량의 비율에 따라 여러 가지 조건에서 RF-magnetron sputtering 시스템을 이용하여 상온에서 증착하였다. Ar과 $O_2$ gas의 비율에 따라 제작된 TFT 소자는 모두 enhancement 모드의 소자특성을 나타내었고, 또한 가시광선영역에 있어 80% 이상의 높은 투과율을 보였다. ZnO 증착시 순수 Ar을 사용하여 제작된 ZnO-TFT의 경우에, $1.2\;cm^2/Vs$의 field effect mobility, 8.5 V의 threshold voltage, 그리고 $5{\times}10^5$의 높은 on/off ratio, 1.86 V/decade의 swing voltage로 가장 우수한 전기적 특성을 보였다.

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