• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.167-170
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• 1998

The electrical characteristics of Stearic acid LB films were investigated to develop the gas sensor using Langmuir-Blodgett(LB) films. The deposition status of LB films were verified by the measurements of UV absorbance and I-V characteristics. The conductivity of Stearic acid LB films at room temperature was $10^{-8}[S/cm]$, which is typical of semiconductor. The conductivity was found to increase as the temperature was increased. The acitivation energy was about 1[eV].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.171-174
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• 1998

Quartz crystal in contact with viscoelastic medium is described directly in terms of the electrical equivalent circuit of the system. Stearic acid is used as viscoelastic medium and deposited on the surface of quartz crystal using the Langmuir-Blodgett(LB) method. Impedance properties of quartz crystal coated with LB films which were investigated and the possibility of applying the technique to chemical sensing introduced.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.146-149
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• 1999

Langmur-Blodgett (LB) method has a unique characteristic of making molecularly mutilayered aggregation structures. LB method makes the thickness of organic insulation layer controllable at molecular scale in various electronic devices. In this study, the organic materials applicable to crosslinked LB insulation layers of electronic devices have developed and the electrical properties of their LB films have examined such as Brewster angle microscopy(BAM), Scanning Maxwell-stress microscopy(SMM), and Current-voltage(1-V) properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.347-349
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• 1999

We have fabricated insulating thin films using p-hexadecoxyphenol(p-Hp) that was formed phenol-formaldehyde resin of crosslinked structure from reaction with formaldehyde by LB technique. For fabricated MIM device, the possibility for insulating layers of electronic were investigated by electrical properties of their LB films according to crosslinking of LB films current-voltage (I-V) properties and frequency-capacitance (C-F) characteristics. We have provided evidence for the high insulating performance of phenol-formaldehyde thin films by the LB method. Conductivity of their LB films was as follows: pure water > 1 % aq. Formaldehyde > heat treatment, in the current-voltage (I-V) characteristics. It is demonstrated that insulation properties of crosslinked p-HP LB films were improved. In capacitance-frequency properties, the heat-treated p-HP LB films for crosslinking showed a low relative dielectric constant.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.12
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• pp.1115-1121
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• 1998

MLS capacitor with lipid ultra thin films were deposited by Langmuir-Blodgett (LB) method on the silicon 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-$\alhpa$-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.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.10
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• pp.820-825
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• 1998

We deposited stearic acid LB films by using Langmuir-Blodgett (LB)method and investigated anisotropy electrical conduction characteristics by I-V measurement for horizontal direction and vertical direction. Also, we measured gad response between deposited LB films and organic gas for various temperature(0~8$0^{\circ}C$) by 9MHz At-cut quartz crystal microbalance. The LB films have electrical conduction characteristics such as semiconducting and insulating properties. The is, the conductivity of LB films for the horizontal and vertical direction is about 10\ulcornerS/cm and 10\ulcorners/cm, respectively. the frequency shift of stearic acid LB films for the organic gases depended on the mass change by the surface adsorption and the inner penetration to the sensing films. The resonant frequency shift of the quartz crystal microbalance for temperature properties of LB films is thought to the effect of the rearrangement or the damage pf LB films above the melting point and the mobility increasement of the organic gas by the temperature rising.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.419-422
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• 1998

There are lots of researches which are using quratz crystal in order to apply it to sensors, for example, mass detect sensor, humidity sensor, gas sensor, etc. We tried to apply quartz crystal to the sensor using the resonant frequency and the resistance properties. Four kinds of fatty acid which are having the same head group are coated at the surface of quartz crystal, the shift of the resonant frequency and the resistance are observed according to length of the tail group. Myristic acid$(C_{14})$, palmitic acid$(C_16)$, stearic acid$(C_{18})$, and arachidic acid$(C_{20})$ were coated by Langmuir-Blodgett(LB) technique. As results, the resonant frequency shift was observed linearly. However, there are some difference compared with Sauerbrey's equation. It can be explained by the effect of the temperature property and/or humidity. On the other hand, the shift of the resistance was observed nonlinearly.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.789-794
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• 2015

In this study, we investigated the stability with respect to the Langmuir-Blodgett(LB) monolayer films of stearic acid and phospholipid(L-${\alpha}$-dimyristoylphosphatidyl choline, DMPC) mixture. LB films of stearic acid and DMPC monolayer were deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $0.05N\;NaClO_4$ solution, -0.3 V initial, 1650 mV switching potential and -1350 mV final potential. As a result, monolayer LB films of stearic acid and phospholipid mixture was appeared on irreversible process caused by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of stearic acid and DMPC mixture(molar ratio 1:1, 1:2, 1:3) was calculated $1.4{\times}10^{-3}$, $1.7{\times}10^{-3}$ and $1.6{\times}10^{-3}(cm^2/s)$ in $0.05N\;NaClO_4$ solution, respectively.