• 제목/요약/키워드: Organic monolayers

검색결과 101건 처리시간 0.035초

A Study on the Negative Differential Resistance in Dipyridinium Self-Assembled Monolayers Using STM

  • Lee Nam-Suk;Shin Hoon-Kyu;Kwon Young-Soo
    • KIEE International Transactions on Electrophysics and Applications
    • /
    • 제5C권3호
    • /
    • pp.111-114
    • /
    • 2005
  • Organic monolayers were fabricated onto Au(l l l) substrate by self-assembly method using dipyridinium. Also, organic single molecule in the organic monolayers was selected to measure the current-voltage (I-V) curves by using the ultrahigh vacuum scanning tunneling microscopy (UHV-STM). The organic molecule used in the experiment was dipyridinium dithioacetate, which contains thiol functional group and can be self-assembled easily onto Au(l l l) substrate. The concentration of dipyridinium dithioacetate for self-assembly procedure was I [mM/L]. To confirm the formation of self-assembled mono layers (SAMs), the differences of thickness of the self-assembled organic monolayers were observed by using an ellipsometer, and the morphology and I-V curves of the SAMs were investigated by using UHV-STM. The applied voltages were from -2 [V] to +2 [V], temperature was 300 [K]. The vacuum for measuring current of the organic single molecule was 6 $\times$ 10$^{-8}$ [Torr]. As a result, properties of the negative differential resistance (NDR) in constant voltage were found.

Structural Control and Two-Dimensional Order of Organic Thiol Self-Assembled Monolayers on Au(111)

  • 노재근
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
    • /
    • pp.26-26
    • /
    • 2011
  • Self-assembled monolayers (SAMs) prepared by sulfur-containing organic molecules on metal surfaces have drawn much attention for more than two decades because of their technological applications in wetting, chemical and biosensors, molecular recognition, nanolithography, and molecular electronics. In this talk, we will present self-assembly mechanism and two-dimensional (2D) structures of various organic thiol SAMs on Au(111), which are mainly demonstrated by molecular-scale scanning tunneling microscopy (STM) observation. In addition, we will provide some idea how to control 2D molecular arrangements of organic SAMs. For instance, the formation and surface structure of pentafluorobenzenethiols (PFBT) self-assembled monolayers (SAMs) on Au(111) formed from various experimental conditions were examined by means of STM. Although it is well known that PFBT molecules on metal surfaces do not form ordered SAMs, we clearly revealed for the first time that adsorption of PFBT on Au(111) at $75^{\circ}C$ for 2 h yields long-range, well-ordered self-assembled monolayers having a $(2{\times}5\sqrt{13})R30^{\circ}$ superlattice. Benzenethiols (BT) SAMs on gold usually have disordered phases, however, we have clearly demonstrated that the displacement of preadsorbed cyclohexanethiol self-assembled monolayers (SAMs) on Au(111) by BT molecules can be a successful approach to obtain BT SAMs with long-range ordered domains. Our results will provide new insight into controlling the structural order of BT or PFBT SAMs, which will be very useful in precisely tailoring the interface properties of metal surfaces in electronic devices.

  • PDF

유기단분자막의 전극거리에 따른 전류 측정 (The Current Measurement by Electrode Distance of Organic Monolayers)

  • 이경섭;전동규;오재한;강용철
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
    • /
    • pp.169-172
    • /
    • 1998
  • We have investigates a surface pressure, a displacement current and a charge measurement by distance of between electrode 1 and water surface of organic monolayers. And the displacement current was generated during compression of Arachidic acid mono1ayers at a air-water interface. The result from our work show that the displacement current of a Langmuir(L) film for Arachidic acid monolayers has the different maximum points according to the electrode distance. We are known that the displacement current and a charge was generated in inverse proportion to electrode distance d.

  • PDF

Study on Charge Transport in Nanoscale Organic Monolayers for Molecular Electronics Using Liquid Phase Electrodes

  • Hwang, Jin-Ha
    • 마이크로전자및패키징학회지
    • /
    • 제12권3호
    • /
    • pp.235-241
    • /
    • 2005
  • Incorporation of solid electrodes frequently involves plasma-based processing. The effect of plasma can influence the physical characteristics, depending on the magnitude in plasma. The undesired feature of plasma-induced damage should be prevented in characterizing the ultra-thin materials, such as ultra-thin films and organic monolayers. The current work at first proves the applicability of a liquid phase electrode in the electrical/dielectric properties through comparative work using Al and Hg on ultrathin $Al_2O_3$ films deposited through atomic layer deposition at low temperature: Two types of metals such as Aluminum (Al) and mercury (Hg) were used as electrodes in $Al_2O_3$ thin films in order to investigate the effect of electrode preparation on the current-voltage characteristics and impedance features as a function of thickness in $Al_2O_3$ film thickness. The success of Hg in $Al_2O_3$ thin films is applied to the AC and DC characterization of the organic monolayers obtained using the Langmuir-Blodgett method. From the DC current-voltage characteristics, the diode-like response is found to originate from the bulk response of the organic materials, evidenced by the fact and the capacitance is inversely related to the absolute thickness of organic layers.

  • PDF

Transport of Organic Cations across Caco-2 Cell Monolayers

  • Kim, Kyong;Chung, Suk-Jae;Shim, Chang-Koo
    • 대한약학회:학술대회논문집
    • /
    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
    • /
    • pp.415.1-415.1
    • /
    • 2002
  • Apical to basal transport of organic cations (OCs) such as tributylmethylammonium (TBuMA), triethyimethylammonium (TEMA). 1-methyl-4-phenylpyridinium (MPP), and berberine across Caco-2 cell monolayers was measured to elucidate the intestinal absorption of OCs. Basal to apical transport of MPP and berberine was larger than apical to basal transport and showed temperature dependency and concentration dependency. indicating that MPP and berberine are secreted into the inteslinal lumen. (omitted)

  • PDF

Arac. acid와 인지질 유기단분자의 자격특성에 관한 연구 (A Study on the Stimulus Properties of Arac. acid and Phospholipid Organic Monolayer)

  • 송진원;이경섭
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
    • /
    • pp.104-107
    • /
    • 2000
  • 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 the measurement of the surface potential or displacement current, are also useful for investigating dynamic changes of the molecular state on the water surface during compression. Maxwell-Displacement-Current(MDC) measuring technique has been applied to the study of monolayers of Arachidic acid and L-$\alpha$-Dimyristoyl Phosphatidylcholine(L-$\alpha$-DMPC). The displacement current was generated from monolayers on a water surface by monolayer compression. Displacement current was generated in the gas state, gas/liquid state, and liquid state in the course of monolayer compression. The researchers examined diplacement current of electric conduction organic monolayer generated due to orient change of monolayers alkylchain.

  • PDF

유기 자기조립 단분자막의 레이저 포토 패터닝을 이용한 박막 미세 형상 가공 기술 (Micromachining Thin Film Using Femtosecond Laser Photo Patterning Of Organic Self-Assembled Monolayers.)

  • 최무진;장원석;김재구;조성학;황경현
    • 한국정밀공학회지
    • /
    • 제21권12호
    • /
    • pp.160-166
    • /
    • 2004
  • Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated fer applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecule and bio molecule. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAMs structure formation.

유기 자기조립 단분자막의 레이저 포토 패터닝을 이용한 금속 박막의 미세 형상 가공 기술 (Micromachining Thin Metal Film Using Laser Photo Patterning Of Organic Self-Assembled Monolayers)

  • 최무진;장원석;신보성;김재구
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2003년도 춘계학술대회 논문집
    • /
    • pp.219-222
    • /
    • 2003
  • Self-Assembled Monolayers(SAMs) by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecular and bio molecular. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance in selective etching of thin metal film of Self- Assembled Monolayers. In this report, we present the micromachining thin metal film by Mask-Less laser patterning of alknanethiolate Self-Assembled Monolayers.

  • PDF

Thin Film Micromachining Using Femtosecond Laser Photo Patterning of Organic Self-assembled Monolayers

  • Chang Won-Seok;Choi Moo-Jin;Kim Jae-Gu;Cho Sung-Hak;Whang Kyung-Hyun
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제7권1호
    • /
    • pp.13-17
    • /
    • 2006
  • Self-Assembled Monolayers (SAMs) formed by alkanethiol adsorption to thin metal film are widely being investigated for applications as coating layer for anti-stiction or friction reduction and in fabrication of micro structure of molecules and bio molecules. Recently, there have been many researches on micro patterning using the advantages of very thin thickness and etching resistance of Self-Assembled Monolayers in selective etching of thin metal film. In this report, we present the several machining method to form the nanoscale structure by Mask-Less laser patterning using alknanethiolate Self-Assembled Monolayers such as thin metal film etching and heterogeneous SAM structure formation.