• Title/Summary/Keyword: surface morphology

Search Result 3,447, Processing Time 0.033 seconds

Effects of Charge-discharge Rate on Morphology and Resistance of Surface Film on a Graphite Negative Electrode in an Ethylene Carbonate-based Solution (탄산 에틸렌계 용액 중에서 생성되는 흑연 음극 표면피막의 형상 및 저항에 미치는 충방전 속도의 영향)

  • Jeong, Soonki;Kim, Pogyom
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.24 no.2
    • /
    • pp.179-185
    • /
    • 2013
  • The behavior of surface film formation was greatly dependent on the speed of potential cycling. In $LiClO_4$ / EC + DEC, cyclic voltammetry results showed that the peaks originated from surface film formation on graphite electrode at the high charge-discharge rate was shifted to the lower potentials as the charge-discharge rate decrease. This indicates that surface films with different morphology and thickness were formed by different charge-discharge rate. Transmission electron microscopy (TEM) results indicated that the properties such as thickness and morphology of the surface film were greatly affected by the charge-discharge rate. Electrochemical impedance spectroscopy (EIS) showed that the resistance of surface film was affected by the speed of potential cycling. In addition, the charge transfer resistance was also dependent on the charge-discharge rate indicating that the charge transfer reaction was affected by the nature of surface film. TEM and EIS results suggested that the chemical property as well as the physical property of the surface film was affected by the charge-discharge rate.

Nanotube Morphology Control of Ti-30Nb-xTa Alloys by Applied Voltages

  • Kim, Eun-Sil;Choe, Han-Cheol
    • Proceedings of the Korean Institute of Surface Engineering Conference
    • /
    • 2013.05a
    • /
    • pp.78-78
    • /
    • 2013
  • This study has investigated the nanotube morphology control of Ti-30Nb-xTa alloys by applied voltages. The morphology changed from small diameter to large diameter with increasing applied voltage, whereas, changed from large diameter to small diameter with decreasing applied voltage.

  • PDF

Photoluminescence property of vertically aligned ZnO nanorods.

  • Das, S.N.;Kar, J.P.;Choi, J.H.;Myoung, J.M.
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2009.11a
    • /
    • pp.25.2-25.2
    • /
    • 2009
  • Vertically aligned zinc oxide(ZnO) nanorods (NRs) with different surface morphology were grown by metal organic chemical vapor deposition (MOCVD) on sapphire substrate with different deposition condition. Based on the surface morphology, ZnO nanostructures are divided into three types: nanoneedles, nanonails and nanorods with rounded tip. Variable temperature photoluminescence (PL) have employed to probe the exciton recombination in high density and vertically aligned ZnO Nanorod arrays. Low temperature photoluminescence measurements do not show any significant yellow emission, but the near band edge excitonic emission shows very strong dependence with the surface morphology. The recombination properties are expected to be different due to different surface-to-volume ratio and distribution of potential fluctuations of intrinsic defects.

  • PDF

A Measurement Method of Three-Dimensional Surface Morphology Based on Depth-from-Focus through Linear Magnification Calibration (선형배율보정을 통한 DFF 기반의 삼차원 형상 측정법)

  • Kim, Gyung-Bum;Shin, Young-Su
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.22 no.9 s.174
    • /
    • pp.115-122
    • /
    • 2005
  • Errors resulting from magnification variations of a optical system are largely generated in three-dimensional shape measurements based on depth-from-focus. In the case of measuring the surface morphology of tiny objects based on DFF, images are acquired with a very small interval so that magnification changes can be minimized. However, the magnification variations are actually existed in the acquired images and so focus measures are wrongly or ambiguously extracted. In this paper, a methodology with linear magnification calibrations, based on DFF, is proposed to make more accurate measurement in surface morphology with high depth discontinuity, compared with previous ones. Several experiments show that the proposed method outperforms existing ones without magnification calibrations.

Research Issues of Electrostatic Spray Deposition (ESD) Technique (정전기 분무 증착법에 대한 최근 연구 동향 고찰)

  • Ryu, Sung-Uk;Lee, Sang-Yong
    • Journal of ILASS-Korea
    • /
    • v.11 no.1
    • /
    • pp.7-16
    • /
    • 2006
  • Performance of thin films fabricated with the electrostatic spray deposition (ESD) technique is strongly governed by surface morphology, which depends on deposition parameters such as deposition time and temperature, solution properties, and surface characteristics of substrates. In this article, the state of the art on the relationships between the surface morphology and the deposition parameters is presented. Also studies on the electro-hydrodynamic atomization process and the motion of drops relevant to the ESD technique are briefly reviewed, and the future research works are suggested.

  • PDF

The Surface Morphology of Polymer Langmuir Film (고분자 Langmuir 박막의 표면형상)

  • Jung, Chi-Sup
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.1
    • /
    • pp.81-88
    • /
    • 2005
  • The Langmuir monolayers of polyamic acid salts with three kinds of alkyl chains have been investigated by means of conventional $\pi$-A isotherms and second harmonic generation measurements proposed in this paper. The surface molecular density dependence of second harmonic intensity clearly shows the region of aggregation while corresponding $\pi$-A isotherm doesn't show any changes in the surface morphology at the same region. The surface morphology analysis based on the second harmonic measurement was consistent with the Brewster angle microscope measurement results.

Surface morphology of Al cathode for OLED with Kr gas (Kr가스에 의한 OLED용 Al 음전극의 표면 형상)

  • Kim, Hyun-Woong;Keum, Min-Jong;Kim, Kyung-Hwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.11a
    • /
    • pp.283-284
    • /
    • 2005
  • Al electrode for OLED was deposited by Facing Targets Sputtering(FTS) system which can reduce the damage of organic layer. The Al thin films were deposited on the slide glass as a function of working gas such as Ar, Kr or mixed gas. The film surface image was observed by AFM and SEM. In the results, when Al thin film were deposited using mixed gas, the surface morphology was improved in some region.

  • PDF

Enhancement of the Surface Smoothness of Cu Ribbon for Solar Cell Modules

  • Cho, Tae-Sik;Cho, Chul-Sik
    • Transactions on Electrical and Electronic Materials
    • /
    • v.16 no.1
    • /
    • pp.20-24
    • /
    • 2015
  • We studied the relationship between the surface smoothness of the internal Cu ribbon and the morphology of the Sn-Pb plating layer for solar cell modules. A bumpy surface was observed on the surface of the solar ribbon, which caused irregular reflection of light. Large, Pb-rich, primary ${\alpha}$-phases were found below the convex surface of the solar ribbon, passing from the surface of the internal Cu ribbon to the surface of the plating layer. The primary ${\alpha}$-phases heterogeneously nucleated on the convex surface of the Cu ribbon, and then largely grew to the convex surface of the plating layer. The restriction of the primary ${\alpha}$-phase's formation was enabled by enhancing the smoothness of the Cu ribbon's surface; it was also possible to increase the adhesive strength and decrease contact resistance. We confirmed that the solar ribbon's surface smoothness depends on the internal Cu ribbon's surface smoothness.

The Effect of Seed Orientation on Growth Form and Surface Morphology in Growing NYAB Crystal (NYAB 결정육성시 종자정의 방향이 성장외형 및 표면형상에 미치는 영향)

  • 정선태;최덕용
    • Korean Journal of Crystallography
    • /
    • v.5 no.2
    • /
    • pp.93-99
    • /
    • 1994
  • Growth form and surface morphology of NYAB single crystal grown by TSSG technique using a K2O/3MoOS/0.5B203 flux was investigated. In the crystal grown from <100> or <120> seed, prismatic and (101) faces were well developed with different size each other. (001) face was also developed in the crystal grown from <001> seed. While growth hillocks were observed on the prismatic face of the crystal grown from <100> seed, surface striations parallel to neighbor (101) faces were formed on that face of the crystal grown from <001> seed. The (101) faces were grown by two dimensional nucleation growth. (001) face which was developed at slow growth velocity of [001] direction was grown by screw dislocation Anisotropy of growth velocity as to seed orientation affected on crystal morphology and surface morphology.

  • PDF