• Title/Summary/Keyword: Langmuir films

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Molecular Orientation and Polarized Absorption Characteristics of N-docosylquinolium-TCNQ LB Film (N-docosylquinolium-TCNQ LB막의 분자배향과 편광특성)

  • Choi, Kang-Hoon;Shin, Dong-Myung;Han, Won-Keun;Park, Tae-Kon;Kang, Dou-Yol
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.868-870
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    • 1992
  • Langmuir-Blodgett method is the best candidate for the development of the future molecular electronic devices. But, this molecular thin film devices requires the bulk properties that was influenced by the molecular arrangements and orientations. So, these are of current interest in molecular electronic device fabrications of new materials. In this experiment, the N-docosylquinolium-TCNQ LB films were deposited on the surface pressures of 30 mN/m and 45 mN/m. We measured the polarized UV/visible absorptions of deposited films for the study of the molecular arrangements and orientations. The polarized UV/visible absorption variation on the incidence and polarization angle of the LB film deposited on the surface pressure of 45 mN/m shown methodically variated. So, we concluded that the LB film deposited on 45 mN/mwas arranged better than that obtained at 30 mN/m.

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Etching characteristics and modeling of BST thin films using inductively coupled plasma (유도결합 플라즈마를 이용한 BST 박막의 식각 특성 및 모델링)

  • Kim, Gwan-Ha;Kim, Kyoung-Tae;Kim, Dong-Pyo;Lee, Cheol-In;Kim, Tae-Hyung;Kim, Chang-Il
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.29-32
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    • 2004
  • This work was devoted to an investigation of etching mechanisms for $(Ba,Sr)TiO_3$ (BST) thin films in inductively coupled $CF_4/Ar$ plasma. We have found that an increase of the Ar content in $CF_4/Ar$ plasma causes non-monotonic behavior of BST etch rate, which reaches a maximum value of 40 nm/min at 80% Ar. Langmuir probe measurements show a weak sensitivity of both electron temperature and electron density to the change of $CF_5/Ar$ mixing ratio. O-D model for plasma chemistry gave monotonic changes of both volume densities and fluxes for active species responsible for the etching process. The analysis of surface kinetics confirms the possibility of non-monotonic etch rate behavior due to the concurrence of physical and chemical pathways in ion-assisted chemical reaction.

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Surface Structure Image of Stearic acid Organic Thin Films (Stearic acid 유기박막의 표면주고 Image)

  • Chang, Hun;Song, Jin-Won;Choi, Young-Il;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.562-564
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    • 2001
  • Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic matter thin film that accumulate molecular film in archaism board only that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it. Formation that prevent when gas phase state and liquid phase state measure but Could know organic matter that molecules form equal and stable film when molecules were not distributed evenly. and accumulated in solid state only.

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Long term life-time of electrochromic poly (3-hexyl thiophene) films modified by surfactant-assisted graphene oxide layers. (계면활성제 기반 산화그래핀층이 도입된 전기변색 poly (3-hexyl thiophene) 박막의 장기 수명 특성)

  • Kim, Tae-Ho;Choe, Gi-In;Kim, Hye-Ri;O, Seong-Hyeon;Gu, Ja-Seung;Na, Yun-Chae
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2016.11a
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    • pp.147-147
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    • 2016
  • In general, organic electrochromic (EC) materials have been known to be electrochemically unstable during the ionic exchange process. One effective method to realize stable EC materials is incorporating graphene derivatives in the polymer matrix, by using the strong interaction between graphene derivatives and polymer. However, previous studies are limited graphene derivatives. In this study, we developed a polymer-graphene derivative complex with the chemical assistance of a surfactant (octadecylamine, ODA). Surfactant-assisted graphene oxide (GO-ODA) was introduced as a protective layer on the electrochromic poly (3-hexyl thiophene) (P3HT) films by the Langmuir-Schaefer method. The deposition of GO-ODA protective layer with high coverage was confirmed by atomic force microscopy. The strong interactions between GO-ODA and P3HT were examined with UV-Vis spectrophotometry and X-ray photoelectron spectroscopy. Electrochemical and electrochromic investigations revealed that the GO-ODA layer greatly improved the long-term cyclability of the P3HT film. These findings imply that the GO-ODA complex has a significant role in creating stable EC cycling, due to its strong interaction with the P3HT film.

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Surface Analysis and Electrical Properties for Complex with Concentration of Metal ion in LB Ultra-thin Films Using IMI-O Polymer (IMI-O 고분자 LB막의 금속 이온의 착체 농도에 따른 전기특성 및 표면분석)

  • Jung, S.B.;Yoo, S.Y.;Park, J.C.;Kwon, Y.S.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1711-1713
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    • 2000
  • We fabricated an IMI-O polymer containing an imidazole group that could form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the surface analysis and the electrical properties of metal ion complex of Langmuir-Blodgett (LB) films were investigated by using $\pi$-A isotherms. Atomoic force microscopy (AFM), current-voltage (I-V) measurements. In the $\pi$-A isotherms the molecular area was expanded with $Fe^{3+}$ concentration increase. It is considered that the expansion of molecular area is due to electrostatic repulsion between the polymer chains and hydrophobic increase of ionic strength. In the I-V characteristics, it is found that the limiting area has effects on the change of conductivity. And, the dielectric relaxation time decreased for increase of the $Fe^{3+}$ concentration.

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Molecular Behavior and Electro-Chemical Properties of Dendrimer and Staff-type Polymer Monolayers in Crown Function Group (크라운 기능기를 포함한 덴드리머 및 Staff-type 고분자 단분자막의 분자거동 및 전기ㆍ화학적 특성)

  • 장정수
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.5
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    • pp.213-213
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    • 2003
  • We investigated the monolayer behavior at the air-water interface with metal solution, the surface morphologies and the electrical properties such as conductivity, The calculated conductivity values of pure water subphase and its complexes with L $i^{+}$ ions are 5.6$\times$10$^{-l6}$ and 1.9$\times$10$^{-14}$ [S/cm], respectively. And the calculated barrier height D values of pure water subphase and its complexes with Li. ions are 0.70 and 0.66 [eV], respectively. We also attempted to fabricate a crown dendrimer Langmuir-Blodgett (LB) films containing functional end group that could form a complex structure with metal ions. Also, we investigated the surface activity of dendrimer films at air-water interface. In AFM images. the larger domains irregularly shaped structures on the top while the smaller ones were free from such defects. In conclusion, it is demonstrated that the metal ion around dendrimer and polymer included crown function group can contribute to make formation of network structure among crown function group and result in change of electrical properties.s.s.

Molecular Behavior and Electro-Chemical Properties of Dendrimer and Staff-type Polymer Monolayers in Crown Function Group (크라운 기능기를 포함한 덴드리머 및 Staff-type 고분자 단분자막의 분자거동 및 전기ㆍ화학적 특성)

  • 장정수
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.5
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    • pp.213-218
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    • 2003
  • We investigated the monolayer behavior at the air-water interface with metal solution, the surface morphologies and the electrical properties such as conductivity, The calculated conductivity values of pure water subphase and its complexes with L $i^{+}$ ions are 5.6$\times$10$^{-l6}$ and 1.9$\times$10$^{-14}$ [S/cm], respectively. And the calculated barrier height D values of pure water subphase and its complexes with Li. ions are 0.70 and 0.66 [eV], respectively. We also attempted to fabricate a crown dendrimer Langmuir-Blodgett (LB) films containing functional end group that could form a complex structure with metal ions. Also, we investigated the surface activity of dendrimer films at air-water interface. In AFM images. the larger domains irregularly shaped structures on the top while the smaller ones were free from such defects. In conclusion, it is demonstrated that the metal ion around dendrimer and polymer included crown function group can contribute to make formation of network structure among crown function group and result in change of electrical properties.s.s.

Surface Structure Image of Stearic acid Organic Thin Films (Stearic acid 유기박막의 표면구조 Image)

  • Chang, Hun;Song, Jin-Won;Choi, Young-Il;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.562-564
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    • 2001
  • Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic matter thin film that accumulate molecular film in archaism board only that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. The stable images are probably due to a strong interaction between the monolayer film and glass substrate. We are unable to obtain molecule resolution in images of the films but did see a marked contrast between images of the bare substrate and those with the network structure film deposited onto it. Formation that prevent when gas phase state and liquid phase state measure but Could know organic matter that molecules form equal and stable film when molecules were not distributed evenly, and accumulated in solid state only.

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A Study on Electrical Properties of Dendrimer (덴드리머의 전기적 특성 연구)

  • Choi, Yong-Sung;Song, Jin-Won;Lee, Woo-Ki;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • 2006.07c
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    • pp.1330-1332
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The agobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the Presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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Phase Transition of Biology Thin Film and Molecule Arrangement Properties (생체박막의 상전이와 분자배열특성)

  • Kim, Byung-Geun;Chon, Dong-Kyu;Kim, Young-Keun;Gu, Hal-Bon;Lee, Woo-Sun;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05c
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    • pp.103-106
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    • 2003
  • It is well known that the state of existence of molecules on the surface of water changes during compression of the molecules. Electric methods, such as measurement of the surface potential or displacement current are also useful for investigating dynamic changes of molecular state on the water surface during compression. In this paper, We studied on the Bio thin film by Langmuir-Biodgett(LB) method. The Experiment method used displacement current, $\pi-A$ isotherm and BAM (Brewster Angle Microscopy). using the BAM, we can to the molecular orientation of monolayer on the water surface and directly see the morphology of the films on water subphase as well as that of the films.

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