• Title/Summary/Keyword: Surface Morphology

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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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    • 2011.02a
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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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Enhanced Electrochromic Performance by Uniform Surface Morphology of Tungsten Oxide Films (텅스텐산화물 막의 균일한 표면 형상에 의한 향상된 전기변색 성능)

  • Kim, Kue-Ho;Koo, Bon-Ryul;Ahn, Hyo-Jin
    • Korean Journal of Materials Research
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    • v.28 no.7
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    • pp.411-416
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    • 2018
  • Tungsten oxide($WO_3$) films with uniform surface morphology are fabricated using a spin-coating method for applications of electrochromic(EC) devices. To improve the EC performances of the $WO_3$ films, we control the heating rate of the annealing process to 10, 5, and $1^{\circ}C/min$. Compared to the other samples, the $WO_3$ films fabricated at a heating rate of $5^{\circ}C/min$ shows superior EC performances for transmittance modulation(49.5 %), response speeds(8.3 s in a colored state and 11.2 s in a bleached state), and coloration efficiency($37.3cm^2/C$). This performance improvement is mainly related to formation of a uniform surface morphology with increased particle size without any cracks by an optimized annealing heating rate, which improves the electrical conductivity and electrochemical activity of the $WO_3$ films. Thus, the $WO_3$ films with a uniform surface morphology prepared by the optimized annealing heating rate can be used as a potential candidate for performance improvement of the EC devices.

Effect of Surface Morphology and Adhesion Force on the Field Emisson Properties of Carbon Nanotube Based Cathode (탄소나노튜브 캐소드의 전계방출 특성에 대한 표면 형상과 부착력의 영향)

  • Jung, Hyuk;Cho, You-Suk;Kang, Young-Jin;Kim, Do-Jin
    • Korean Journal of Materials Research
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    • v.18 no.5
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    • pp.277-282
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    • 2008
  • The effects of the field emission property in relation to the surface morphology and adhesion force were investigated. The single-wall-nanotube-based cathode was obtained by use of an in-situ arc discharge synthesis method, a screen-printing method and a spray method. The morphologies of the formed emitter layers were very different. The emission stability and uniformity were dramatically improved by employing an in-situ arc discharge synthesis method. In this study, it was confirmed that the current stability and uniformity of the field emission of the cathode depend on the surface morphology and adhesion force of the emitters. The current stability of the field emission device was also studied through an electrical aging process by varying the current and electric field.

Cross-section Morphology and Surface Roughness of an Article Manufactured by Material Extrusion-type 3D Printing according to the Thermal Conductivity of the Material

  • Woo, In Young;Kim, Do Yeon;Kang, Hong Pil;Lyu, Min-Young
    • Elastomers and Composites
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    • v.55 no.1
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    • pp.46-50
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    • 2020
  • Material extrusion (ME)-type 3D printing is the most popular among the 3D printing processes. In this study, the cross-section morphologies of ME-type 3D printing manufactured specimens were observed with respect to the thermal properties of the material. The cross-section morphology of a specimen is related to the deposition strength, and the outside profile of the cross-section is related to the surface roughness. The filaments used in this study, with different thermal conductivities, were the acrylonitrile-butadiene-styrene (ABS), the high impact polystyrene (HIPS), the glycol-modified polyethylene terephthalate (PETG), and the polylactic acid (PLA). The cross-sections and the surfaces of the 3D manufactured specimens were examined. In ME-type 3D printing, the filaments are extruded through a nozzle and they form a layer. These layers rapidly solidify and as a result, they become a product. The thermal conductivity of the material influences the cooling and solidification of the layers, and subsequently the cross-section morphology and the surface roughness.

Growth and Characterization of Vertically Aligned ZnO nanowires with different Surface morphology

  • Das, S.N.;Choi, J.H.;Kar, J.P.;Myoung, J.M.
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.35.1-35.1
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    • 2009
  • Vertically aligned zinc oxide (ZnO) nanorods (NRs) with different surface morphology were grown by metal organic chemical vapor deposition (MOCVD) on sapphire substrate. The films thus prepared were characterized by measuring X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) studies. To study the effect of surface morphology on wettability, the contact angle (CA) of water was measured. It was demonstrated that the CA of the deposited ZnO NRs varied between $104^{\circ}$ and $135^{\circ}$ depending upon the surface morphology. Variable temperature photoluminescence (PL) have employed to probe the exciton recombination in high density and vertically aligned ZnO Nanorod arrays. The low-temperature PL characterizes the dominant near-band-edge excitonic emissions from such nanorod arrays.

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The Evolution of Preferred Orientation and Morphology of NiO Thin Films under Variation of Plasma gas and RF Sputtering Power (플라즈마 가스와 RF 파워에 따른 NiO 박막의 우선배향성 및 표면형상 변화)

  • Ryu Hyun-Wook;Choi Gwang-Ryo;Noh Whyo-Sup;Park Yong-Ju;Kwon Yong;Park Jin-Seong
    • Korean Journal of Materials Research
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    • v.14 no.2
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    • pp.121-125
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    • 2004
  • Nickel oxide (NiO) thin films were deposited on Si(100) substrates at room temperature by RF magnetron sputtering from a NiO target. The effects of plasma gas and RF power on the crystallographic orientation and surface morphology of the NiO films were investigated. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were employed to characterize the deposited film. It was found that the type of plasma gases affected the crystallographic orientation, deposition rate, surface morphology, and crystallinity of NiO films. Highly crystalline NiO films with (100) orientation were obtained when it was deposited under Ar atmosphere. On the other hand, (l11)-oriented NiO films with poor crystallinity were deposited in $O_2$. Also, the increase in RF power resulted in not only higher deposition rate, larger grain size, and rougher surface but also higher crystallinity of NiO films.

A study on the growth morphology of AlN crystals grown by a sublimation process (승화법으로 성장된 AlN 결정의 성장 양상에 관한 연구)

  • Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.19 no.5
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    • pp.242-245
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    • 2009
  • AlN crystals were grown by a sublimation process without seed crystals and the growth morphology of them was characterized. The grown AlN crystals were a polycrystalline phase, which had a diameter of $60\sim200\;{\mu}m$ and were grown with a growth rate of $0.2\sim0.5\;{\mu}n/hr$. It was observed that the as-grown crystals had a hexagonal crystal structure and revealed that these crystals were grown with a morphology of columnar morphology in the initial stage of the growth before they were enlarged in a way of a lateral growth behavior in the final stage. On the surface, a lot of pinholes were observed on the surface of crystals grown. The evolution of a growth morphology was characterized by optical and scanning electron microscopic observation.

Study on Nickel Plating of Leadframe using Pulse Technique (펄스법을 이용한 리드프레임의 니켈도금에 관한 연구)

  • Chung W.S.;Min B.S.;Lim J.J.;Chung U.C.
    • Journal of the Korean institute of surface engineering
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    • v.36 no.3
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    • pp.242-250
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    • 2003
  • Electrodeposition of Ni was carried out on copper substrate from Ni Sulfamate bath by DC and high frequency pulse current. During the electroplating, bath temperature was steady $60^{\circ}C$ , agitation was applied. Morphology and surface roughness of electrodeposits was investigated with the AFM. Crystalline structure of electrodeposits was investigated with XRD. Also, surface electric resistivity was investigated with 4-point probe. The result of crystalline structure by X-ray diffractometer, in the case of DC, <200> direction was dominant growing direction. But in the case of PC, the ratio of <200> direction vs. other direction decreased. As the pulse frequency increased, the enhanced properties of deposits were shown. With increasing frequency, the degree of surface properties increased DC more than that of PC, eg surface morphology, roughness and the degree of compactness of grains. With increasing duty cycle, the surface properties such as the degree of the morphology, roughness and electroconductivity was deteriorated.

Evaluation of the Machining Method on the Formation of Surface Quality of Upper Electrode for Semiconductor Plasma Etch Process (반도체 플라즈마 에칭 상부 전극의 표면 품질 형성에 관한 가공법 평가)

  • Lee, Eun Young;Kim, Moon Ki
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.4
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    • pp.1-5
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    • 2019
  • This study has been focused on properties of surface technology for large diameter upper electrode using in high density plasma process as like semi-conductor manufacturing process. The experimental studies have been carried out to get mirror surface for upper electrode. For a formation of high surface quality upper electrode, single crystal silicon upper electrode has been mechanical and chemical machining worked. Mechanical machining work of the upper electrode is carried out with varying mesh type using diamond wheel. In case of chemical machining work, upper electrode surface roughness was observed to be strongly dependent upon the etchant. The different surface roughness characteristics were observed according to etchant. The machining result of the surface roughness and surface morphology have been analyzed by use of surface roughness tester, laser microscope and ICP-MS.

EFFECT OF DIFFERENT STERILIZATION METHODS ON THE SURFACE MORPHOLOGY OF PPDO-hybrid-PLGA NANOFIBER SCAFFOLD AND ATTACHMENTS OF PC12 CELL (다양한 소독방법이 PPDO-hybrid-PLGA nanofiber scaffold의 형태와 세포부착에 미치는 영향에 관한 연구)

  • Lee, Ju-Hyon;Min, Hyun-Gi;Jung, Ju-Young;Kang, Na-Ra
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.34 no.6
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    • pp.635-639
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    • 2008
  • Objectives : the effect of different sterilization methods on the surface morphology of PPDO-hybrid-PLGA nanofiber scaffold and attachments of PC12 cell were investigated. Methods : Poly (p-dioxone)-hybrid-Poly (lactide-glycolide) (PPDO-hybrid-PLGA) nanofiber scaffold, fabricated in a tube form with 1.5 mm internal diameter, 0.2 mm thickness and 5 mm length, was prepared using electrospinning method. To study the surface morphology using SEM, The study group and control group in respective were; Control:Non-sterilized scaffold, Group I:scaffold sterilized with 70% Alcohol, Group II: scaffold sterilized with Ethylene Oxide at $65^{\circ}C$, and Group III: scaffold sterilized with Ethylene Oxide at $37^{\circ}C$. To investigate viability of the PC12 cell on the scaffold, The study group and control group in respective were; Control: sterilized with 70% Alcohol, Group I: sterilized with Ethylene Oxide at $65^{\circ}C$, and Group II: sterilized with Ethylene Oxide at $37^{\circ}C$. Results : 1. The surface morphology was slightly changed in Group I, II and Group III, compared with control. 2. The attachment of PC12 cells in Group I, II was not higher than in control Discussion : The attachment of PC12 cell is not influenced by different sterilization methods.