• 제목/요약/키워드: self-assembled layer

검색결과 140건 처리시간 0.026초

Study of Self-assembled Organic Layer Formation at the HATCN/Au Interface

  • Kim, Ji-Hoon;Won, Sangyeon;Kwon, Young-Kyun;Kahng, Se-Jong;Park, Yongsup
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.150.2-150.2
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    • 2013
  • We elucidate the mechanism of the self-assembled organic layer formation at the organic/metal interface of hexaaza-triphenylene-hexacarbonitrile (HATCN)/Au(111) by first-principles calculations and Lowtemperature scanning tunneling microscope (STM). In this work, we used HATCN to deposit organic material which is well known as an efficient OLED charge generation material. Low-temperature STM measurements revealed that self-assembled hexagonal porous structure is formed at terraces of Au(111). We also found that the hexagonal porous structure has chirality and forms only small (<1000 $nm^2$) phaseseparated chiral domains that can easily change their chiral phase in subsequence STM images at 80 K. To explain the mechanism of these observation, we calculated the molecular-molecular and molecule-surface interaction energies by using density functional theory method. We found that the change of their chiral phase resulted from the competition between the two energies. These results have not only verified our experimental observations, but also revealed the delicate balance between different interactions that caused the self-assembed structures at the surface.

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SAM 절연체를 이용한 유기박막트랜지스터 개발의 최근 동향 (Recent Trends in the Development of Organic Thin Film Transistor Including SAM Dielectric)

  • 김성수
    • 통합자연과학논문집
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    • 제2권1호
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    • pp.13-17
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    • 2009
  • A newly developed OTFT manufacturing process using the combination of self-assembly techniques and vapor phase polymerization method revealed that a thick $SiO_2$ dielectric layer (100~200 nm) is not well compatible with conducting polymer electrode, thereby resulting in still recognizable contact resistance, unstable $V_{th}$ and leaking off current. A couple of very recent studies showed that this issue may be solved by replacing such inorganic dielectric with a self-assembled monolayer or multilayer (organic) dielectric. Therefore, this short review introduces recent trends in the development of high performance thin film transistor consisting of both organic semiconductor and SAM dielectric.

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UHV STM을 이용한 유기 초박막의 전기적 특성 연구 (Electrical Characteristics of Self-Assembled Organic Thin Films Using Ultra-High Vacuum Scanning Tunneling Microscopy)

  • 김승언;신훈규;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.108-111
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    • 2003
  • Currently, molecular devices are reported utilizing active self-assembled monolayers containing the nitro group as the active component, which has active redox centers[1]. We confirm the electrical properties of 4,4-di(ethynylphenyl)-2'-nitro-1-benzenethiolate. To deposit the SAM layer onto gold electrode, we transfer the prefabricated Au(111) substrates into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured current-voltage curve using ultra high vacuum scanning tunneling microscopy (UHV STM), I-V curve also clearly shows several current peaks between the negative bias region (-0.3958V) and the positive bias region (0.4658V), respectively.

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Study of CVD Growth Single-walled Carbon Nanotubes via Catalytic Layer Supported by Self-assembled Monolayer

  • Adhikari, Prashanta Dhoj;Kim, Sung-Hwan;Song, Woo-Seok;Lee, Su-Il;Park, Chong-Yun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.402-402
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    • 2012
  • Bundles of single-walled carbon nanotube (SWCNTs) were grown using catalytic layer supported by self-assembled monolayers (SAMs). Amine-SAMs were introduced on SiO2/Si substrate (SAMs/Si) there then iron nanoclusters solution was dropped on it through spin-coating (Fe/SAMs/Si). This catalytic template was used to grow CNTs and the synthesized carbon material was confirmed the bundles of dense SWCNTs with incorporation of ca.1% nitrogen. The SAMs has played an active role to support catalytic layer and also acted as a source of N-dope onto SWCNTs in CVD.

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나노성형 공정 조건이 자기조립 단분자막의 이형 특성에 미치는 영향 (The Effect of Process Condition in Nano-molding on the Property of SAM (self-assembled monolayer))

  • 이남석;한정원;강신일
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 추계학술대회 논문집
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    • pp.83-86
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    • 2005
  • In this study, SAM (self-assembled monolayer) was applied as an anti-adhesion layer in the nano molding process, to reduce the surface energy between the nano-stamper and the moldeded polymeric nano patterns. Before depositing SAM on the stamper, the nickel stamper was pretreated to remove oxide on the nickel stamper surface. Then, using the solution deposition method, alkanethiol SAM as an anti-adhesion layer was deposited on nickel surface. To examine the effectiveness of the SAM deposition on the metallic nano stamper, the contact angle and the lateral friction force were measured at the actual processing temperature and pressure for the case of nano compression molding and at the actual UV dose for the case of nano UV molding. The surface energy due to SAM deposition on the nickel nano stamper markedly decreased and the high hydrophobic quality of SAM on the nickel stamper maintained under the actual molding environments.

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Surface Potential Change Depending on Molecular Orientation of Hexadecanethiol Self-Assembled Monolayers on Au(111)

  • Ito, Eisuke;Arai, Takayuki;Hara, Masahiko;Noh, Jaegeun
    • Bulletin of the Korean Chemical Society
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    • 제30권6호
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    • pp.1309-1312
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    • 2009
  • Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

Threshold Voltage Shift in (4-pentylphenylethynyl)-dithienyl-anthracene Organic Thin-film Transistor with Self-assembled Monolayer

  • Lee, Sun-Hee;Kim, Sung-Hoon;Han, Seung-Hoon;Choi, Min-Hee;Jeong, Yong-Bin;Choo, Dong-Joon;Jang, Jin
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.858-860
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    • 2009
  • We have applied self-assembled monolayer to make high performance and stable OTFT on the organic gate dielectric. The ${\beta}$-phenethyltrichlorosilane (SAM) was coated on the organic gate dielectric and then active layer was printed. Significant improvements in on-currents and threshold voltage shift were achieved for the SAM treated devices compared to device without SAM.

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Effect of self-assembled monolayer and aluminum oxide ALD film on a PMMA substrate

  • Shin, Sora;Park, Jongwan
    • Journal of Ceramic Processing Research
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    • 제19권6호
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    • pp.525-529
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    • 2018
  • The antireflective (AR) coated poly methyl methacrylate (PMMA) substrate was deposited by atomic layer deposition (ALD) on a self-assembled monolayer (SAM) to improve hydrophobicity and mechano-chemical properties of organic thin films. The water contact angles (WCA) were tested to characterize the surface wettability of SAM octadecyltrichlorosilane (OTS) films. Results showed that a contact angle of $105.9^{\circ}$ was obtained for the SAM films with an annealing process, and the highest WCA of $120^{\circ}$ was achieved for the films prepared by the SAM and ALD multi-process. The surface morphology of the SAM films with different assembly times and varying number of ALD cycles was obtained by atomic force microscopy (AFM). The maximum light transmittance for the SAM films on the PMMA substrate reached 99.9% at a wavelength of 450 nm. It was found that the SAM surfaces were not affected at all by the ALD process.