• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.231-233
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• 1994

We have studied a properly of N-docosyl pyridinium(TCNQ) Langmuir-Blodgett film at room temperature with the $NO_2$ gas-detection characteristics. As a result, we have found that their conductivities were increased by 6 times at 5 layers(about $250{\AA}$ thickness) LB film. However, their reproducibility was not able to be measured at room temperature. Therefore, we must find their working temperature which was able to activate gas-detection characteristics. The $NO_2$ gas response experiments under 200 ppm concentration in $50^{\circ}C$ show that :here are increment of electrical conductivity by 8 times and 100 seconds of response time, and 200 seconds of recovery times at $60^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.549-553
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• 1998

The structure and layer distribution of cadmium arachidate Langmuir-Blodgett film were analyzed by the small angle X-ray reflectivity measurements using synchrotron radiation. Y-to X type transition was ocurred during the 39th passage of deposition of cadmium arachidate. Based on the measurement of the consumed area of the monolayer, it was determined that about 27.5 layer was deposited. Using the synchrotron X-ray, the reflectivity profile of cadmium arachidate LB film over the wide range of grazing angle was obtained. The X-ray reflectivity profile was analyzed using the recursion formula. By fitting the location and dispersion of the subsidiary maxima between the Bragg peaks of the measured reflectivity profile with that of the calculated reflectivity profile, the average thickness and the distribution of layer thickness were evaluated. The genetic algorithm was adopted to the fitting of reflectivity profile to evaluate the optimum value of the number distribution of layer. Based on the morphology measurement with an atomic force microscopy (AFM), the domain structure and mean roughness of LB films were obtained. The mean roughness value calculated based on the number of layer distribution obtained from the measurement by AFM is consistent with that obtained from X-ray reflectivity analysis.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1247-1249
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• 1997

Langmuir-Blodgett(LB) method is one of the ways of fabricating organic ultra thin films. It is well known that It has the advantage to control the alignment and orientation of the molecules in the films. Metallo-phthalocyanines (MPcs) are sensitive to electron affinitive toxic gaseous molecules, such as $NO_2$, NO, $SO_2$. In this study, thin films of octa-dodecyloxy copper-phthalocyanine were prepared by LB method and characterized by using UV/Vis absorption spectroscopy and ellipsometry. Optimal transfer condition of LB films was investigated and preliminary results of current-voltage (I-V) characteristics of these films exposed to $NO_2$ gas as a function of film thickness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.298-301
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• 1997

This paper describes the thermally stimulated current(TSC) measurements arachidic acid(AA) and polyamic acid alkylamine salts(PAAS) LB film, which is a precursor of polyimide(PI). The measurements were performed from room temperature to about 250$^{\circ}C$ and the temperature was increased at a rate of 0.02 $^{\circ}C$/s linearly[4]. It shows that peaks of TSC are observed at about 80$^{\circ}C$ in the arachidic acid and about 80$^{\circ}C$, 160$^{\circ}C$ in the PAAS LB films. The DSC and TGA of PAAS, arachidic acid are measure. Monolayer phases on the water subphase such as Langmuir(L) films and the phase transitions from gas phase to solid phase via liquid phase are observed using Brewster angle microscopy(BAM). BAM is also used to observe the Langemuir-Blodgett(LB) films.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.43-44
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• 2002

Langmuir-Blodgett mono- and multilayer films from 2,4-heneicosanedione have been examined as lubrication coatings In the process of wear. Tribological properties of the films have been studied by atomic force microscopy and microtribometer. It has been observed that the wear resistance of silicon surface coated with OTS/LB multilayer system increased by several orders of magnitude compared to uncoated surfaces at low normal load. The results obtained suggest that the system constructed on silicon surface reduces surface energy, friction coefficient and increases life of substrate due to a possibility of LB film self-repairing during frictional contact.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.05a
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• pp.230-233
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• 1995

Using Polyimide Langmuir-Blodgett(LB) films as a tunneling barrier, Current -Voltage(I-V) characteristics and inelastic electron tunneling spectroscoupy(IETS) of the junctions incorporating 1-layer orgainc monolayer were invesgated. Several peaks originating in vibrational modes of constituted molecules of 1-layer monolayers were clearly observed in the IET spectra.

• Transactions on Electrical and Electronic Materials
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• v.6 no.1
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• pp.18-21
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• 2005

Monolayers of lipids on a water surface have attracted much interest as models of biological membranes, but also as precursors of multilayer systems promising many technical applications. Until now, many methodologies have been developed in order to gain a better understanding of the relationship between the structure and function of the monolayers. Maxwell displacement current (MDC) measurement has been employed to study the dielectric property of Langmuirfilms. MDC flowing across monolayers is analyzed using a rod-like molecular model. A linear relationship between the monolayer compression speed a and the molecular area Am. Compression speed a was about 30, 40, and 50 mm/min. Langmuir-Blodgett(LB) layers of Arachidic acid deposited by LB method were deposited onto slide glass as Y-type film. The structure of manufactured device is Aul Arachidic acid! AI, the number of accumulated layers are $9{\sim}21$. Also, we then examined of the Metal-Insulator-Metal(MIM) device by means of I-V. The I-V characteristics of the device are measured from -3 to+3 V. The insulation property of a thin film is better as the distance between electrodes is larger.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.155-158
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• 1998

MLS capacitor with lipid ultra thin films were deposited by Langmuir-Blodgett (LB) method on the sillicon wafer. The current versus voltage and capacitance versus voltage relationships are depend on the applied voltage, electrode area and electrode materials. LB films deposited were made of L-$\alpha$-DLPC, the 1 layer's thickness of 35$\AA$ was measured by ellipsometer. And MLS capacitor with different electrode materials, the work function of these materials was investigated to increase the leakage current. The result indicated the lower leakage current and very high saturation value of capacitance was reached within 700-800 pF when the two electrode was Ag. And $\varepsilon$$_1$, $\varepsilon$$_2$ versus photon energy showed good film formation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.75-78
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• 1994

Organic ultra thin films about 500${\AA}$ in thickness are fabricated by LB(Langmuir-Blodgett) technique and their gas detect properties are investigated. The LB films deposited are made of the specimen named as N-docosyl pyridinium(TCNQ) and the deposition is verified by capacitance conductivity measurement. From the study of gas detect properties with I-V characteristics and UV spectrum we have found that their conductivities were increased about 3 times of magnitude and peaks of UV spectrum were decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.1-4
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• 1997

In this study, ruin films of Octla-dodecyloxy copper-phthalocyanine were prepared by Langmuir-Blodgett (LB) method and characterirzed by using UV-Vis absorption spectroscopy and ellipsometry. [1],r[2] Optimal transfer condition of LB films was investigated and preliminary results of current-voltage(1-V) characteristics of these films exposed to NO$_2$ gas as were discussed functions of film thickness, temperature and NO$_2$ gas concentration.