• Title, Summary, Keyword: Double layer

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A study on improvement of amorphous silicon solar cell using i-double layer (i-double layer를 사용한 박막태양전지 특성향상에 관한 연구)

  • Jang, Juyeon;Song, Kyuwan;Yi, Junsin
    • 한국신재생에너지학회:학술대회논문집
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    • pp.115.1-115.1
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    • 2011
  • 최근 기본적인 pin 구조의 박막 cell 에서 i layer를 최적화 시키는 방안으로 double layer 구조가 많이 연구되고 있다. 본 연구에서는 ASA(Advanced Semicon ductor Analysis) simulation을 이용하여 i-double layer 최적화에 대한 연구를 진행해 보았다. 두께 150/150nm의 i double layer의 band gap 가변을 한 simulation 결과를 보았을 때, p쪽의 band gap이 상승하면서 intrinsic layer 내의 field가 증가하여 recombination center가 감소하였으나 FF의 감소가 있었다. n쪽의 band gap을 상승 시켰을때 n/i 쪽 field 증가로 Voc가 상승되어 초기 효율이 증가하였으나 intrinsic layer내의 field가 감소하여 recombination center가 오히려 증가하였다. 결과적으로 electric field와 효율을 동시에 고려했을 때 두께 300nm, 1.75의 band gap을 가지는 single layer 보다 150/150nm두께에 1.8/1.7 또는 1.8/1.75의 bandgap을 가지는 double layer를 사용하였을 때 보다 높은 효율을 얻을 수 있었다.

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Comparison of Environmental Conditions and Insulation Effect between Air Inflated and Conventional Double Layer Greenhouse (공기주입 및 관행 이중피복온실의 재배환경 및 단열성능 비교)

  • Jayasekara, Shanika N.;Na, Wook H.;Owolabi, Abdulhameed B.;Lee, Jong W.;Rasheed, Adnan;Kim, Hyeon T.;Lee, Hyun W.
    • Protected Horticulture and Plant Factory
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    • v.27 no.1
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    • pp.46-53
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    • 2018
  • This study was conducted to determine which greenhouse provided good environmental conditions for strawberry production, and performed better at conserving energy. Temperature, RH, VPD, $CO_2$, solar radiation, yield, and fuel consumption were the parameters analyzed. The temperatures of both greenhouses were well controlled in order to provide optimal day and night temperatures for strawberry production. The air inflated double layer greenhouse had higher RH values (more than 90% at night), which led to higher disease occurrence, in comparison to the conventional double layer greenhouse. Furthermore, the air inflated double layer greenhouse had lower VPD values than the conventional double layer greenhouse. Therefore, better RH and VPD were observed in the conventional double layer greenhouse. Higher $CO_2$ concentration was observed in the air inflated double layer greenhouse while the conventional double layer greenhouse ventilated better than the air inflated greenhouse, because of its side ventilators. Moreover, higher solar radiation in the conventional double layer greenhouse resulted in higher yield, in comparison to the air inflated double layer greenhouse. Thus, we can conclude that the conventional double layer greenhouse provided a better environment for crop growth, in comparison to the air inflated double layer greenhouse. Regarding fuel consumption, the air inflated double layer greenhouse had lower fuel consumption than the conventional double layer greenhouse. Therefore, from an energy consumption point of view, we can conclude that the air inflated double layer greenhouse performed better than the conventional double layer greenhouse.

Variations of Adsorption Characteristics of Binary Vapor According to Packing System of Double-layer Adsorption Bed (2중층 흡착층의 충전방법에 따른 2성분 증기의 흡착특성 변화)

  • Lee, Min-Gyu;Lee, Song-Woo;Kam, Sang-Kyu;Lee, Seok-Hee
    • Journal of Environmental Science International
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    • v.21 no.3
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    • pp.305-312
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    • 2012
  • This work is to study the variations of adsorption characteristics of binary vapor according to packing system of double-layer bed by fixed bed experiment. Breakthrough curves of single and binary vapor composed of acetone and benzene on single-layer and double-layer adsorption bed composed of activated carbon (AC) and silica-aluminar (SA) were compared. Adsorptions of binary vapor on double-layer bed were influenced by the differences of surface area between adsorbents as well as the polarity difference between adsorbent and adsorbate. The roll-up phenomenon of acetone vapor was happened by replacement with competing adsorption between acetone vapor and benzene vapor on AC bed, but it was not happened on SA bed because acetone vapor and benzene vapor had less difference in affinity with SA bed. The breakthrough times of acetone vapor and benzene vapor on AC/SA double-layer bed were three times and 1.4 times larger respectively than on SA/AC double-layer bed, the differences of breakthrough times were relatively larger than the equilibrium adsorption capacities according to packing system of double-layer bed.

Double Layer (Wet/CVD $SiO_2$)의 Interface Trap Density에 대한 연구

  • Lee, Gyeong-Su;Choe, Seong-Ho;Choe, Byeong-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.340-340
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    • 2012
  • 최근 MOS 소자들이 게이트 산화막을 Mono-layer가 아닌 Multi-Layer을 사용하는 추세이다. Bulk와 High-k물질간의 Dangling Bond를 줄이기 위해 Passivation 층을 만드는 것을 예로 들 수 있다. 이러한 Double Layer의 쓰임이 많아지면서 계면에서의 Interface State Density의 영향도 커지게 되면서 이를 측정하는 방법에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 $SiO_2$ Double Layer의 Interface State Density를 Conductance Method를 사용하여 구하는 연구를 진행하였다. Wet Oxidation과 Chemical Vapor Deposition (CVD) 공정을 이용하여 $SiO_2$ Double-layer로 증착한 후 Aluminium을 전극으로 하는 MOS-Cap 구조를 만들었다. 마지막 공정은 $450^{\circ}C$에서 30분 동안 Forming-Gas Annealing (FGA) 공정을 진행하였다. LCR meter를 이용하여 high frequency C-V를 측정한 후 North Carolina State University California Virtual Campus (NCSU CVC) 프로그램을 이용하여 Flatband Voltage를 구한 후에 Conductance Method를 측정하여 Dit를 측정하였다. 본 연구 결과 Double layer (Wet/CVD $SiO_2$)에 대해서 Conductance Method를 방법을 이용하여 Dit를 측정하는 것이 유효하다는 것을 확인 할 수 있었다. 본 실험은 앞으로 많이 쓰이고 측정될 Double layer (Wet/CVD $SiO_2$)에 대한 Interface State Density의 측정과 분석에 대한 방향을 제시하는데 도움이 될 것이라 판단된다.

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Structure and Optical Properties of the Ca/Ag Double Layer for Transparent Cathode in TEOLED

  • Kim, Boo-Kyung;Moon, D.G.;Ahn, B.T.
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1071-1074
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    • 2006
  • Ca/Ag double layer which is fabricated by thermal evaporation exists as the double layer of (Ca+O)/(Ag+Ca). In Ca layer, are crystalline Ca(OH)2 and amorphous Ca and in Ag layer, are crystalline Ag and amorphous Ca. And for the certain thickness of Ag, in the Ca/Ag double layer, the thicker Ca is, the higher transmittance is.

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The Thickness of a Sensitive Emulsion on the Double Layer Screen Plate (이중층 스크린 인쇄판에 도포된 감광유제의 두께)

  • Jung, Gi-Young;Kang, Young-Reep
    • Journal of the Korean Printing Society
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    • v.29 no.3
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    • pp.125-132
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    • 2011
  • Is very simple in tension work of screen mesh for effective printing if worker uses screen mesh of player who desire at screen print process. General method is methods that use mesh of player who want on screen frame as screen plate because tensioned. The single layer screen plate was made from one sheet screen mesh and the double layer screen plate was made from two sheets screen mesh overlapped. The thickness of sensitive emulsion applied to double layer screen plate is more thicker than two time s of thickness of emulsion applied to single layer screen plate. It seems that the sensitive emulsion inserted between an upper layer and a lower layer of double layer screen mesh.

Study on the eletronic absorption and surface morphology of phthalocyanine double layer thin films

  • Heo, Il-Su;Ryu, Il-Hwan;Hong, Da-Jeong;Im, Sang-Gyu
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.337-337
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    • 2011
  • The elecronic absorption and surface morphology evolution of two types of molecular double layer thin films, copper phthalocyanine(CuPc) layer deposited on top of chloro[subphtalocyaninato]boron(III) (SubPc) layer, denoted as SubPc/CuPc, and vice versa, at various thicknesses were invertigated using ultraviolet(UV)-visible spectroscopy and atomic force microscopy (AFM). Both types of double layer structures showed similar broadened absorption patterns in UV-visible region which were well consistent with fitted spectra by a simple linear combination of single layer absorption spectra of two materials. In contrast, the surface morphology of double layer structures was dependent on the order of deposition. For CuPc/SubPc structures, the surface morphology was characterized by elongated grains, characteristic of SubPc thin films, indicating the morphological influence of underlying CuPc layer on subsequent SubPc layer was not large. For SubPc/CuPc structures, however, the underlying SubPc layer acted as a morphological template for the subsequently deposited CuPc layer. It was also observed that the grain size of CuPc layer varied by the thickness of underlying SubPc layer.

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Temperature History of Slab Concrete Depending on Insulation Curing Method in Cold Weather Concreting (한중시공시 단열양생방법 변화에 따른 슬래브 콘크리트의 온도이력 특성)

  • Kim Jong-Back;Lim Choon-Goun;Park Koo-Byoung;Kim Seoung-Soo;Han Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.17-20
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    • 2005
  • This paper reported the temperature history of concrete placed at deck plate slab under cold climate condition by varying with surface insulating type. No curing sheet and simple insulation curing including non-woven fabric, double layer bubble sheet, the combination of double layer bubble sheet and non-woven fabric dropped temperature below zero within 24 hours, which caused frost damage at early age. On the other hand, the combination of double layer bubble sheet and non-woven fabric and double layer bubble sheet and styrofoam maintained minimum temperature above $4^{\circ}C\;and\;8^{\circ}C$, respectively. Based on core test results compressive strength of concrete with the combination of double layer bubble sheet and non-woven fabric and double layer bubble sheet and styrofoam was higher than those with other curing method due to good insulation effect.

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A study on the nonvolatile memory characteristics of MNOS structures with double nitride layer (2층 질하막 MNOS구조의 비휘발성 기억특성에 관한 연구)

  • 이형욱
    • Electrical & Electronic Materials
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    • v.9 no.8
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    • pp.789-798
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    • 1996
  • The double nitride layer Metal Nitride Oxide Semiconductor(MNOS) structures were fabricated by variating both gas ratio and nitride thickness, and by duplicating nitride deposited and one nitride layer MNOS structure to improve nonvolatile memory characteristics of MNOS structures by Low Pressure Chemical Vapor Deposition(LPCVD) method. The nonvolatile memory characteristics of write-in, erase, memory retention and degradation of Bias Temperature Stress(BTS) were investigated by the homemade automatic .DELTA. $V_{FB}$ measuring system. In the trap density double nitride layer structures were higher by 0.85*10$^{16}$ $m^{-2}$ than one nitride layer structure, and the AVFB with oxide field was linearly increased. However, one nitride layer structure was linearly increased and saturated above 9.07*10$^{8}$ V/m in oxide field. In the erase behavior, the hole injection from silicon instead of the trapped electron emission was observed, and also it was highly dependent upon the pulse amplitude and the pulse width. In the memory retentivity, double nitrite layer structures were superior to one nitride layer structure, and the decay rate of the trapped electron with increasing temperature was low. At increasing the number on BTS, the variance of AVFB of the double nitride layer structures was smaller than that of one nitride layer structure, and the trapped electron retention rate was high. In this paper, the double nitride layer structures were turned out to be useful in improving the nonvolatile memory characteristics.

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Effects of Blending Ratio of Pigments on Properties and Printability of the Double Coated Paper (안료의 배합비가 더블 도공지의 물성 및 인쇄적성에 미치는 영향)

  • Kim, Chang-Keun;Lee, Yong-Kyu
    • Journal of Forest and Environmental Science
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    • v.18 no.1
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    • pp.97-105
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    • 2001
  • The main objective of this study was to investigate effects of pigment mixed with different ratio on the double coated paper. Mineral pigments such as clay and ground calcium carbonate(GCC) as well as hollow sphere plastic pigment were used to evaluate the physical, optical properties and printabilities of double coated paper. The physical properties such as gloss and smoothness, and the printability(ink gloss) of double coated paper were measured to evaluate the effects of the bottom layer on improving the properties of top layer. The data indicated that the usage of hollow sphere plastic pigment for the bottom layer coating improved the surface properties of double coated paper, and that ink gloss was significantly influenced by the structure of bottom layer even when hollow sphere plastic pigment was used for the bottom layer coating.

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