• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.205-206
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• 2011

Cu thin films for electromagnetic wave shielding were prepared on PET film and Ni-coated PET film by using Dry and Wet coating method, such as evaporation method, DC sputtering method and copper sulfate($CuSO_4$). After that, Zn thin film and Ni thin film were prepared onto the Cu thin films by using evaporation dry process and Ni electro plating wet process as a finishing treatment, respectively. The result of conductivity test and corrosion resistance test revealed Cu thin films which were formed with bigger grain size and high Cu composition rate have superior properties. Zn thin film by dry evaporation process and Ni thin film by wet electro plating process on Cu thin films were largely contributed to corrosion resistance. However, Ni thin film by wet process made conductivity of all specimen worse, the other hand, Zn thin film by dry process made it better to improve condictivity of specimens just prepared by dry process.

• Journal of Surface Science and Engineering
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• v.55 no.2
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• pp.63-69
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• 2022

Preparing various types of thin films of oxide semiconductors is a promising approach to fabricate efficient photoanodes and photocathodes for hydrogen production via photoelectrochemical (PEC) water splitting. In this work, we investigate the feasibility of an efficient photocathode for PEC water reduction of a p-type oxide semiconductor cupric oxide (CuO) thin film prepared via a facile method combined with sputtering Cu metallic film on fluorine-doped thin oxide (FTO) coated glass substrate and subsequent thermal oxidation of the sputtered Cu metallic film in dry air. Characterization of the structural, optical, and PEC properties of the CuO thin film prepared at various Cu sputtering powers reveals that we can obtain an optimum CuO thin film as an efficient PEC photocathode at a Cu sputtering power of 60 W. The photocurrent density and the optimal photocurrent conversion efficiency for the optimum CuO thin film photocathode are found to be -0.3 mA/cm² and 0.09% at 0.35 V vs. RHE, respectively. These results provide a promising route to fabricating earth-abundant copper-oxide-based photoelectrode for sunlight-driven hydrogen generation using a facile method.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.52.1-52.1
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• 2009

Cupric oxide (CuO) is a p-type semiconductor with band gap of ~1.7 eV and reported to be suitable for catalysis, lithium-copper oxide electrochemical cells, and gas sensors applications. The nanoparticles, plates and nanowires of CuO were found sensing to NO2, H2S and CO. In this work, we report about the comparison about hydrogen sensing of nano thin film and nanowires structured CuO deposited on single-walled carbon nanotubes (SWNTs). The thin film and nanowires are synthesized by deposition of Cu on different substrate followed by oxidation process. Nano thin films of CuO are deposited on thermally oxidized silicon substrate, whereas nanowires are synthesized by using a porous thin film of SWNTs as substrate. The hydrogen sensing properties of synthesized materials are investigated. The results showed that nanowires cupric oxide deposited on SWNTs showed higher sensitivity to hydrogen than those of nano thin film CuO did.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.193-196
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• 2001

Single phase $CuInS_2$ thin film with the highest diffraction peak (112) at diffraction angle $(2\theta)$ of $27.7^{\circ}$ and the second highest diffraction peak (220) at diffraction angle $(2\theta)$ of $46.25^{\circ}$ was well made with chalcopyrite structure at substrate temperature of $70^{\circ}C$, annealing temperature of $250^{\circ}C$, annealing time of 60 min. The $CuInS_2$ thin film had the greatest grain size of $1.2{\mu}m$ and Cu/In composition ratio of 1.03. Lattice constant of a and c of that $CuInS_2$ thin film was 5.60 A and 11.12 A respectively. Single phase $CuInS_2$ thin films were accepted from Cu/In composition ratio of 0.84 to 1.3. P-type $CuInS_2$ thin films were appeared at over Cu/In composition ratio of 0.99. Under Cu/In composition ratio of 0.96, conduction types of $CuInS_2$ thin films were n-type. Also, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of p-type $CuInS_2$ thin film with Cu/In composition ratio of 1.3 was 837 nm, $3.0{\times}104cm^{-1}$ and 1.48 eV respectively. When Cu/In composition ratio was 0.84, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of n-type $CuInS_2$ thin film was 821 nm, $6.0{\times}10^4cm^{-1}$ and 1.51 eV respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.193-196
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• 2001

Single phase CuInS$_2$ thin film with the highest diffraction peak (112) at diffraction angle (2$\theta$) of 27.7$^{\circ}$ and the second highest diffraction peak (220) at diffraction angle (2$\theta$) of 46.25$^{\circ}$ was well made with chalcopyrite structure at substrate temperature of 70 $^{\circ}C$, annealing temperature of 25$0^{\circ}C$, annealing time of 60 min. The CuInS$_2$ thin film had the greatest grain size of 1.2 ${\mu}{\textrm}{m}$ and Cu/In composition ratio of 1.03. Lattice constant of a and c of that CuInS$_2$ thin film was 5.60 $\AA$ and 11.12 $\AA$ respectively. Single phase CuInS$_2$ thin films were accepted from Cu/In composition ratio of 0.84 to 1.3. P-type CuInS$_2$ thin films were appeared at over Cu/In composition ratio of 0.99. Under Cu/In composition ratio of 0.96, conduction types of CuInS$_2$ thin films were n-type. Also, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of p-type CuInS$_2$ thin film with Cu/In composition ratio of 1.3 was 837 nm, 3.0x10 $^4$ $cm^{-1}$ / and 1.48 eV respectively. When CuAn composition ratio was 0.84, fundamental absorption wavelength, the absorption coefficient and optical energy band gap of n-type CuInS$_2$ thin film was 821 nm, 6.0x10$^4$ $cm^{-1}$ / and 1.51 eV respectively.

• Journal of Surface Science and Engineering
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• v.51 no.4
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• pp.243-248
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• 2018

All solid state thin film batteries with two types of cell structure, Pt / $LiCoO_2$ / LiPON / Cu and Pt / $LiCoO_2$ / LiPON / $LiCoO_2$ / Cu, are prepared and their electrochemical performances are investigated to evaluate the effect of $LiCoO_2$ interlayer at the interface of LiPON / Cu. The crystallinity of the deposited $LiCoO_2$ thin films is confirmed by XRD and Raman analysis. The crystalline $LiCoO_2$ cathode thin film is obtained and $LiCoO_2$ as the interlayer appears to be amorphous. The surface morphology of Cu current collector after cycling of the batteries is observed by AFM. The presence of a 10 nm-thick layer of $LiCoO_2$ at the interface of LiPON / Cu enhances the interfacial adhesion and reduces the interfacial resistance. As a result, Li plating / stripping at the interface of LiPON / Cu during charge/discharge reaction takes place more uniformly on Cu current collector, while without the interlayer of $LiCoO_2$ at the interface of LiPON / Cu, the Li plating / stripping is localized on current collector. The thin film batteries with the interlayer of $LiCoO_2$ at the interface of LiPON / Cu exhibits enhanced initial coulombic efficiency, reversible capacity and cycling stability. The thickness of the anode current collector Cu also appears to be crucial for electrochemical performances of all solid state thin film batteries.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.96-98
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• 2009

This report summarizes our recent efforts to produce large-grained CIGS materials from porous nanoparticle thin films. In our approach, a $Cu_xSe$ nanoparticle colloid were first prepared by reacting a mixture of CuI in pyridine with $Na_2Se$ in methanol at reduced temperature. purified colloid was sprayed onto heated molybdenum-coated sodalime glass substrates to form thin film. After thermal processing of the thin film under a selenium ambient. $Cu_xSe$ colloid and thin film were characterized by scanning electron microscopy, x-ray diffraction. The optical(direct) band gap energy of $Cu_xSe$ thin films is 1.5 eV.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.379-380
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• 2005

Single phase $CuInS_2$ thin film with a highest diffraction peak (112) at a diffraction angle ($2\Theta$) of $27.7^{\circ}$ was well made by SEL method at annealing temperature of $250^{\circ}C$ and annealing hour of 60 min in vacuum of $10^{-3}$ Torr or in S ambience for an hour. And the peak of diffraction intensity at miller index (112) of $CuInS_2$ thin film annealed in S ambience was shown a little higher about 11 % than in only vacuum. Single phase $CuInS_2$ thin films were appeared from 0.85 to 1.26 of Cu/In composition ratio and sulfur composition ratios of $CuInS_2$ thin films fabricated in S ambience were all over 50 atom%. Also when $CuInS_2$ composition ratio was 1.03, $CuInS_2$ thin film with chalcopyrite structure had the highest XRD peak (112). The largest lattice constant of a and grain size of $CuInS_2$ thin film in S ambience was 5.63 ${\AA}$ and 1.2 ${\mu}m$ respectively. And the films in S ambience were all p-conduction type with resistivities of around $10^{-1}{\Omega}cm$.

• Electrical & Electronic Materials
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• v.10 no.9
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• pp.938-944
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• 1997

Cu-Ni thin film strain gauges for diaphragm-type pressure sensors were developed. Thin films of Cu-Ni alloys of various compositions were deposited onto glass and stainless steel substrates by RF magnetron sputtering. The effects of composition substrate temperature Ar partial pressure and aging on the electrical properties of Cu-Ni film strain gauges in the thickness range 500~2000$\AA$ are discussed. The maximum resistivity(95.6 $\mu$$\Omega$cm) is obtained from 53wt%Cu-47wt%Ni films while the temperature coefficient of resistance(TCR) becomes minimum(25.6ppm/$^{\circ}C$). The gauge factor is about 1.9.

• Journal of Surface Science and Engineering
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• v.49 no.1
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• pp.40-45
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• 2016

Recently, $Bi_2Te_3$-based alloys are the best thermoelectric materials near to room temperature, so it has been researched to achieve increased figure of merit(ZT). Ternary compounds such as Bi-Te-Se and Bi-Sb-Te have higher thermoelectric property than binary compound Bi-Te and Sb-Te, respectively. Compared to DC plating method, pulsed electrodeposition is able to control parameters including average current density, and on/off pulse time etc. Thereby the morphology and properties of the films can be improved. In this study, we electrodeposited n-type ternary Cu-doped $Bi_2(Te-Se)_3$ thin film by modified pulse technique at room temperature. To further enhance thermoelectric properties of $Bi_2(Te-Se)_3$ thin film, we optimized Cu doping concentration in $Bi_2(Te-Se)_3$ thin film and correlated it to electrical and thermoelectric properties. Thus, the crystal, electrical, and thermoelectric properties of electrodeposited $Bi_2(Te-Se)_3$ thin film were characterized the XRD, SEM, EDS, Seebeck measurement, and Hall effect measurement, respectively. As a result, the thermoelectric properties of Cu-doped $Bi_2(Te-Se)_3$ thin films were observed that the Seebeck coefficient is $-101.2{\mu}V/K$ and the power factor is $1412.6{\mu}W/mK^2$ at 10 mg of Cu weight. The power factor of Cu-doped $Bi_2(Te-Se)_3$ thin film is 1.4 times higher than undoped $Bi_2(Te-Se)_3$ thin film.