• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.130-130
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• 2016

Bioinspired hierarchical nanostructures for self-cleaning s-tnwjurface and SERS substrates are investigated. The multi-level hierarchy is combined with CuO nanowire and additional nanoscale structures. CuO nanowire, which has extremely high aspect ratio, serves as a base structure of multi-level hierarchy and additional flower like structures are placed on the CuO nanowires. Since as-fabricated CuO nanostructures are hydrophilic, the surface is coated with perfluorooctyltrichlorosilane in order to change its wetting property to hydrophobic. While those CuO based nanostructures have a sufficient roughness for superhydrophobic characteristics, hierarchical nanoflowers on nanowire structures lead to a self-cleaning surface. Furthermore, flower like nanostructures provide reentrant curvatures, thus enabling oleophobic property. The surfaces has a repellency even for a tiny droplet (10 nL) of low surface tension liquids (~35 mN/m). On the on hands, nanoflowers provide many number of nanoscale gaps. After a thin layer of silver is deposited on the surface of CuO nanostructures, those nanoscale gaps act as hot-spot for surface enhanced Raman scattering (SERS). To analyze SERS enhancement of the surfaces, Raman shift is measured with varying molar density of 4-Mercaptopyridine from mM to pM. From these results, hierarchical CuO nanostructures are suitable for self-maintenance and cost effective SERS sensing applications.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.245-245
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• 2009

l-D nanostructured materials have much more attention because of their outstanding properties and wide applicability in device fabrication. Copper oxide(CuO) has been realized as a p-type metal oxide semiconductor with narrow band gap of 1.2 -1.5eV. Copper oxide nanostructures can be synthesized by various growth method such as oxidation reaction, thermal evaporation thermal decomposition, sol-gel. and Mostly CuO nanowire prepared on the Cu substrate such as Copper foil, grid, plate. In this study, CuO NWs were grown by thermal oxidation (at various temperatures in air (1 atm)) of Cu metal deposited on CuO (20nm)/$SiO_2$(250nm)/Si. A 20nm-thick CuO layer was used as an adhesion layer between Cu metal and $SiO_2$

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.315.1-315.1
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• 2014

The use of cellulose papers has recently attracted much attention in various device applications owing to their natural advantageous properties of earth's abundance, bio-friendly, large-scale production, and flexibility. Conventional metal oxides with novel structures of nanorods, nanospindles, nanowires and nanobelts are being developed for emerging electronic and chemical sensing applications. In this work, both ZnO (n-type) nanorod arrays (NRAs) and CuO (p-type) nanospindles (NSs) were synthesized on cellulose papers and the p-n junction property was investigated using the electrode of indium tin oxide coated polyethylene terephthalate film. To synthesize ZnO and CuO nanostructures on cellulose paper, a simple and facile hydrothermal method was utilized. First, the CuO NSs were synthesized on cellulose paper by a simple soaking process, yielding the well adhered CuO NSs on cellulose paper. After that, the ZnO NRAs were grown on CuO NSs/cellulose paper via a facile hydrothermal route. The as-grown ZnO/CuO NSs on cellulose paper exhibited good crystalline and optical properties. The fabricated p-n junction device showed the I-V characteristics with a rectifying behaviour.

• 한국결정성장학회지
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• 제16권4호
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• pp.166-171
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• 2006

층상 구조의 유기-무기 복합 소재 $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$에 마이크로파를 조사하면서 $Cu_2O$와 Cu를 합성하였다. 에틸렌 글리콜에서는 $Cu_2(OH)_3(CH_3COO){\cdot}H_2O$이 환원이 되어서 Cu금속이 형성되는 반면에, 수용액에 글루코오스를 넣으면$Cu_2(OH)_3(CH_3COO){\cdot}H_2O$이 환원이 되어 $Cu_2O$가 형성되었다. 마이크로파 조사시간과 글루코오스의 농도가 $Cu_2O$의 입자의 생성과 성장에 미치는 영향을 확인하였다. 마이크로파의 조사시간이 길어질수록 $Cu_2O$의 입자는 수 ${\mu}m$의 구형에서 40nm의 지름을 가진 나노 선으로 변함을 확인하였다.

• 한국재료학회지
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• 제25권5호
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• pp.238-246
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• 2015

$H_2S$ is a flammable toxic gas that can be produced in plants, mines, and industries and is especially fatal to human body. In this study, CuO nanowire structure with high porosity was fabricated by deposition of copper on highly porous singlewall carbon nanotube (SWCNT) template followed by oxidation. The SWCNT template was formed on alumina substrates by the arc-discharge method. The oxidation temperatures for Cu nanowires were varied from 400 to $800^{\circ}C$. The morphology and sensing properties of the CuO nanowire sensor were characterized by FESEM, Raman spectroscopy, XPS, XRD, and currentvoltage examination. The $H_2S$ gas sensing properties were carried out at different operating temperatures using dry air as the carrier gas. The CuO nanowire structure oxidized at $800^{\circ}C$ showed the highest response at the lowest operating temperature of $150^{\circ}C$. The optimum operating temperature was shifted to higher temperature to $300^{\circ}C$ as the oxidation temperature was lowered. The results were discussed based on the mechanisms of the reaction with ionosorbed oxygen and the CuS formation reaction on the surface.

• 마이크로전자및패키징학회지
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• 제22권1호
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• pp.7-14
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• 2015

Recently, advances in nano-material researches have opened the door for various transparent conductive materials, which include carbon nanotube, graphene, Ag and Cu nanowire, and printable metal grids. Among them, Ag nanowires are particularly interesting to synthesize because bulk Ag exhibits the highest electrical conductivity among all metals. Here we reviewed recently-published research works introducing various devices from organic light emitting diode to tactile sensing devices, all of which are employing AgNW for a conducting material. They proposed methods to enhance the stretchability and reversibility of the transparent electrodes, and apply them to make various flexible and stretchable electronics. It is expected that Ag nanowires are applicable to a wide range of high-performance, low-cost, stretchable electronic devices.

• 마이크로전자및패키징학회지
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• 제30권2호
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• pp.21-32
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• 2023

구리 나노와이어(CuNW)는 전기 전도도가 우수할 뿐만 아니라 높은 기계적 유연성과 비용 효율성 등의 장점이 있다. 그러나 구리 나노와이어는 산화가 쉽게 일어나기 때문에 투명 전극의 특성까지도 저하될 수 있다는 단점 또한 존재한다. 따라서, 이러한 문제점을 해결하기 위한 연구들이 진행되고 있다. 이에 본 고에서는 탄소 기반 물질, 금속, 전도성 고분자 등의 코팅용 소재를 활용하여 구리 나노와이어 투명전극의 산화를 방지하고 안정성을 향상시키기 위한 다양한 방법과 연구를 소개한다. 이를 통해 구리 나노와이어 기반 기술의 발전과 산화에 대한 문제를 해결할 수 있는 방안들을 제공하고자 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.430.1-430.1
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• 2016

We present the concept of reducible fugitive material that conformally surrounds core Cu nanowire (NW) to fabricate transparent conducting electrode (TCE). Reducing atmosphere can corrodes/erodes the underlying/surrounding layers and might cause undesirable reactions such impurity doing and contamination, so that hydrogen-/forming gas based annealing is impractical to make device. In this regards, we introduce novel reducible shell conformally surrounding indivial CuNW to provide a protection against the oxidation when exposed to both air and solvent. Uniform copper lactate shell formation is readily achievable by injecting lactic acid to the CuNW dispersion as the acid reacts with the surface oxide/hydroxide or pure copper. Cu lactate shell prevents the core CuNW from the oxidation during the storage and/or film formation, so that the core-shell CuNW maintains without signficant oxidation for long time. Upon simple thermal annealing under vacuum or in nitrogen atmosphere, the Cu lactate shell is easily decomposed to pure Cu, providing an effective way to produce pure CuNW network TCE with typically sheet resistance of $19.8{\Omega}/sq$ and optical transmittance of 85.5% at 550 nm. Our reducible copper lactate core-shell Cu nanowires have the great advantage in fabrication of device such as composite transparent electrodes or solar cells.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.3.2-3.2
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• 2011

Nanofibers, one of various one-dimensional nanomaterials such as nanorods, nanowires and nanotubes have been successfully synthesized by many groups in recent years and their applications to chemical sensors, catalytic filters and biomedicine, etc. are extensively tested. In particular, there is a possibility that chemical sensors based on oxide nanofibers can overcome the shortcomings of chemical sensors based on single nanowires. In order to prepare oxide nanofibers, the electrospinning method is most widely used. In this work, we synthesized various oxide nanofibers including ZnO, SnO2 and CuO by employing an electrospinning method and various shapes of nanofibers including core-shell nanofibers and hollow nanofibers as well. The response properties of the various nanofibers to oxidizing and reducing gaseous species have been investigated systematically. The normal oxide nanofibers showed high sensitivity and quite fast response time to many gaseous species. Furthermore, derivatives of normal nanofibers including hollow nanofibers, core-shell nanofibers and heterostructured nanofibers display much superior sensing properties. These results hold promise for the practical application of oxide nanofibers to chemical sensors. In addition, the sensing mechanisms operated in the nanofibers will be discussed in detail.

• 한국물환경학회지
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• 제38권2호
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• pp.82-94
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• 2022

In this study, chemically modified biochar (NSBP500, KSBP500, OSBP500) derived from starfish was utilized to improve the adsorption ability of the SBP500 (Starfish Biochar Pyrolyzed at 500℃) in a solution contaminated with heavy metals. According to the biochar modification performance evaluation batch tests, the removal rate and adsorption amount of NSBP500 increased 1.4 times for Cu, 1.5 times for Cd, and 1.2 times for Zn as compared to the control sample SBP500. In addition, the removal rate and adsorption amount of KSBP500 increased 2 times for Cu, 1.8 times for Cd, and 1.2 times for Zn. The removal rate and adsorption amount of OSBP500 increased 5.8 times for Cu. The FT-IR analysis confirmed the changes in the generation and movement of new functional groups after adsorption. SEM analysis confirmed Cu in KSBP500 was in the form of Cu(OH)₂ and resembled the structure of nanowires. The Cd in KSBP500 was densely covered in cubic form of Cd(OH)₂. Lead(Pb) was in the form of Pb₃(OH)₂(CO₃)₂ in a hexagonal atomic layer structure in NSBP500. In addition, it was observed that Zn was randomly covered with Zn₅(CO₃)₂(OH)₆ pieces which resembled plates in KSBP500. Therefore, this study confirmed that biochar removal efficiency was improved through a chemical modification treatment. Accordingly, adsorption and precipitation were found to be the complex mechanisms behind the improved removal efficiency in the biochar. This was accomplished by electrostatic interactions between the biochar and heavy metals and ion exchange with Ca²⁺.