• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2247-2254
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• 2010

The surface structures of copper phthalocyanine (CuPc) thin films deposited on sulphur-passivated and plane perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA)-covered InAs(100) surfaces have been studied by low energy electron diffraction (LEED) and van der Waals (vdW) intermolecular interaction energy calculations. The annealing to $300^{\circ}C$ and $450^{\circ}C$ of $(NH_4)_2S_x$-treated InAs(100) substrates produces a ($1{\times}1$) and ($2{\times}1$) S-passivated surface respectively. The CuPc deposition onto the PTCDA-covered InAs(100) surface leads to a ring-like diffraction pattern, indicating that the 2D ordered overlayer exists and the structure is dominantly determined by the intermolecular interactions rather than substrate-molecule interactions. However, no ordered LEED patterns were observed for the CuPc on S-passivated InAs(100) surface. The intermolecular interaction energy calculations have been carried out to rationalise this structural difference. In the case of CuPc unit cells on PTCDA layer, the planar layered CuPc structure is more stable than the $\alpha$-herringbone structure, consistent with the experimental LEED results. For CuPc unit cells on a S-($1{\times}1$) layer, however, the $\alpha$-herringbone structure is more stable than the planar layered structure, consistent with the absence of diffraction pattern. The results show that the lattice structure during the initial stages of thin film growth is influenced strongly by the intermolecular interactions at the interface.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.181-181
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• 1999

Self-assembled monolayers(SAMs) of alkanethiol have been formed on the Cu(111) surfaces in vacuum. The thermal behavior of octanethiol-based SAMs on the Cu(111) surface have been examined in ultrahigh vacuum. Using X-ray photoelectron spectroscopy (XPS), it is found that the monolayers are stable up to about 500K in vacuum. Decomposition is signaled by a decrease in the intensity of C ls peak, accompanied by an increase of the intensity of the Cu 2p peak. However, the intensity of the S 2p peak doesn't change much as a function of annealing temperature. Thermal the decomposition mass spectra show that n-alkene is the predominant species desorbing from the surface in the 500-600K temperature range. The totality of these data leads to the conclusion that the monolayers decompose through the S-C bond cleavage by hydrogen elimination reaction, resulting in the desorption of hydrocarbon moiety as n-alkene. Following this initial decomposition step, Cu2S layers are observed on the surface. For comparison, attempts were also made to examine the thermal behavior of octanethiol-based SAMs on the Cu(111) surface in air. It has been shown that the SAMs on the Cu(111) surfaces begin to desorb with the oxidation of the thiolate to sulfonate at 400K. Upon annealing to 450K, the monolayer has almost completely desorbed as indicated by the virtual disappearance of the S 2p peak.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.250-251
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• 2014

This study introduces a simple deposition of $Cu_2O$ thin films with surface morphologies composed of columns, submicron-rods and submicron-branches on glass substrate from metallic Cu targets by tailoring the $Ar/O_2$ ratios during the sputtering. The obtained samples were used to fabricate gas sensor. The $H_2S$ sensing properties of the sensors at working temperatures from $100^{\circ}C$ to $300^{\circ}C$ were studied, in which $Cu_2O$ submicron-branches performed the best sensing property comparing with the rest morphologies. A transformation of $Cu_2O$ to $Cu_2S$ and CuS was consider as a main factor to the sensing mechanism of the sensors.

• Journal of the Korean institute of surface engineering
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• v.57 no.2
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• pp.92-97
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• 2024

The LiBr aqueous solution, which is the absorption liquid of absorption refrigerator, must be replaced periodically because the concentration of impurities such as Cu²⁺, Fe²⁺, Ca²⁺, etc., increases due to corrosion of the tubes as the period of use increases, and the refrigeration efficiency decreases significantly. In order to reuse the waste absorption liquid, flocculation-precipitation method is mainly applied to precipitate the impurities, which requires hundreds of times the concentration of impurities and generates additional waste. In this study, a process for removing Cu ion impurities from cyclone electrolyzer by electrolytic reduction is presented in a small-scale facility without additional waste. It was confirmed that Cu ion impurities can be removed down to 1 ppm by electrolytic reduction process, and to further improve the removal rate, the mass transfer rate was increased by using a cyclone electrolyzer. The removal rate of Cu ions increased with the increase of flow rate and current density, and it was confirmed that Cu was removed at a rate of 1.48 ppm/h under the condition of 330 mL/sec and 2.5 mA/cm².

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.256-256
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• 2012

SoP용 재료에 응용하기 위하여 NiCuZn 페라이트계 이용한 이종접합의 관한연구를 하였다. NiCuZn 페라이트계와 유전체의 이종접합특성은 XRD, Dilatometer, LCR meter, FE-SEM, EDS 이용하여 물리 화학적 특성을 조사하였다. NiCuZn 페라이트계는 일반적인 세라믹 제조공정을 이용하여 분말을 제조하였으며, 이종접합은 모든 시편에서 잘 진행되었으며 일부 유전체의 이온들이 페라이트 쪽으로 확산이 진행되었으며 NCZF700계는 $900^{\circ}C$ 소결 시편에서 확산이 진행되지 않은 현상이 나타났다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.758-760
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• 2007

Organic field-effect transistors (OFETs) are of interest for use in widely area electronic applications. We fabricated a copper phthalocyanine (CuPc) based field-effect transistor with different metal electrode. So we need the effect of the substituent group attached to the phthalocyanine on the surface potential was investigated by Kelvin probe method with varying temperature of the substrate. We were obtained the positive shift of the surface potential for CuPc thin film. We observed the electron displacement at the interface between Au electrode and CuPc layer and we were confirmed by the surface potential measurement.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.141-141
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• 2018

Copper is one of the most abundant metals on earth. Its oxide (CuO) is an intrinsically p-type metal-oxide semiconductor with a bandgap ($E_g$) of 1.2-2.0 eV 1. Copper oxide nanomaterials are considered as promising materials for a wide range of applications e.g., lithium ion batteries, dye-sensitized solar cells, photocatalytic hydrogen production, photodetectors, and biogas sensors 2-7. Recently, high-density and uniform CuO nanostructures have been grown on Cu foils in alkaline solutions 3. In 2011, T. Soejima et al. proposed a facile process for the oxidation synthesis of CuO nanobelt arrays using $NH_3-H_2O_2$ aqueous solution 8. In 2017, G. Kaur et al. synthesized CuO nanostructures by treating Cu foils in $NH_4OH$ at room temperature for different treatment times 9. The surface treatment of Cu in alkaline aqueous solutions is a potential method for the mass fabrication of CuO nanostructures with high uniformity and density. It is interesting to compare the gas sensing properties among CuO nanomaterials synthesized by this approach and by others. Nevertheless, none of above studies investigated the gas sensing properties of as-synthesized CuO nanomaterials. In this study, CuO nanowalls versus nanoparticles were synthesized via the oxidation process of Cu foil in NH4OH solution at $50-70^{\circ}C$. The gas sensing properties of the as-prepared CuO nanoplates were examined with $C_2H_5OH$, $CH_3COCH_3$, and $NH_3$ at $200-360^{\circ}C$.

• Applied Chemistry for Engineering
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• v.35 no.1
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• pp.61-65
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• 2024

The effectiveness of CuSCN as a hole injection layer in large-area organic light-emitting diodes, organic solar cells, and thin-film transistors has been well demonstrated. Therefore, in this study, the surface, optical, and electrical analyses of CuSCN were carried out according to the solution process conditions in order to propose optimized film conditions. Various CuSCN solution concentrations were prepared to determine the film surface characteristics and to determine whether the film surface affects the electrical performance of the device. When the CuSCN solution concentration was low, the CuSCN film was not formed and coated in the form of islands, and when the solution concentration was increased, the CuSCN film was formed uniformly, which contributed to improving the conductivity of the device. In addition, a hole-only device was fabricated to demonstrate the role of CuSCN as a hole transport layer.

• Journal of the Korean institute of surface engineering
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• v.28 no.4
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• pp.243-254
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• 1995

The fabrication process of Cu-base anode for replacing Ni-base anode of molten carbonate fuel cell was investigated. Electrochemical performance and thermal stability of Cu-base anode were also investigated. Green sheet was prepared by mixing Cu and Ni powder with 1.5wt% methylcellulose and 100wt% water. The pore-size distribution of the Cu-base anode sintered at $800^{\circ}C$ for 30min showed almost uniform pore-size ranging from 4 to 20$\mu\textrm{m}$ and it was considered suitable for MCFC anode. Cu-Ni anode containing between 35 to 50wt% Ni exhibited current density of 111mA/$\textrm{cm}^2$ at 100mV overpotential and it was almost the some value for pure Ni anode. The sintering resistance of Cu-Ni increased with an increase of Ni addition. It was considered that the increase of sintering resistance was due to the decrease of diffusion rate of Cu and Ni with increasing the addition of Ni in Cu-Ni alloy.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2013.05a
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• pp.183-183
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• 2013

본 연구는 전착법으로 형성된 $Cu_2O$ 박막의 광특성 변화를 고찰한 것이다. 0.3M $CuSO_4$과 4M Lactic acid에 4M NaOH로 전해액의 pH를 조절하여 $Cu_2O$ 박막의 결정성 및 극성을 조절하였다. $Cu_2O$ 박막의 결정성 및 극성에 따른 광특성을 고찰한 결과, 극성인 (111)면에서 광특성이 우수함을 확인하였다. 하지만, 측정시간의 증가에 따라 표면에 Cu 금속이 형성되어 광전류가 감소함을 확인 할 수 있었다. rGO는 페르미전위가 $Cu_2O$ 환원 전위보다 위쪽에 위치한다. 따라서 $Cu_2O$ 박막위에 rGO를 형성시켜 Cu 발생반응을 제한하고 광전류를 증가시키고자한다.