• 한국재료학회지
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• 제18권12호
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• pp.669-672
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• 2008

Well-aligned Zinc oxide (ZnO) nanowires were synthesized on silicon substrates by a carbothermal evaporation method using a mixture of ZnO and graphite powder with Au thin film was used as a catalyst. The XRD results showed that as-prepared product is the hexagonal wurzite ZnO nanostructure and SEM images demonstrated that ZnO nanowires had been grown along the [0001] direction with hexagonal cross section. As-grown ZnO nanowires were coated with glucose oxidase (GOx) for glucose sensing. Glucose converted into gluconic acid by reaction with GOx and two electrons are generated. They transfer into ZnO nanowires due to the electric force between electrons and the positively charged ZnO nanostructures in PBS. Photoluminescence (PL) spectroscopy was employed for investigating the movements of electrons, and the peak PL intensity increased with the glucose concentration and became saturated when the glucose concentration is above 10 mM. These results demonstrate that ZnO nanostructures have potential applications in biosensors.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.399-401
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• 2009

Transparent conductive metal oxide films of $In_{2-x}Ti_xO_3$ (ITiO) and $In_{2-x}Sn_xO_3$ (ITO) were deposited by RF magnetron sputtering at substrate temperature of $300^{\circ}C$ and at high rate (${\sim}10$nm/min). Electrical and optical properties of the films were investigated as well as film structure and morphology, as it is compared with the commercial F:$SnO_2$ (FTO) glass. Near infrared ray transmittance of ITiO is the highest for wavelengths over 1000nm, which can increase dye sensitized compared to ITiO and FTO. Dye-sensitized solar cells (DSCs) were fabricated using the ITiO, ITO and FTO. Photoconversion efficiency (${\eta}$) of DSC using ITiO is 5.5%, whereas 5.0% is obtained from DSC with ITO. both at 100 mW/$cm^2$ light intensity.

• 한국전기전자재료학회논문지
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• 제22권8호
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• pp.682-688
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• 2009

A periodic away of zinc oxide(ZnO) micro-rods as fabricated by using chemical bath deposition and photo-lithography. Vertically aligned ZnO micro-rods array was successfully grown by chemical bath deposition method on ZnO seed layer. The ZnO seed layer was deposited on glass and the patterning was made by standard photo-lithography technique. The selective growth of ZnO micro-rods as achieved with the masked ZnO seed layer. The fabricated ZnO micro rods were found to be single crystalline and have grown along hexagonal c-axis direction of (0002) which is same as the preferred growth orientation of ZnO seed layer.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1683-1685
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• 2003

MgO is making an important role not only as a protective layer but also improves the discharge characteristics at AC PDP. Until now, the substitute of protective layer, MgO has been studied in many ways, but it's too difficult to get a new substitute as stable as MgO. But some problems has been advanced at the discharge characteristics of MgO on high temperature. So we studied the discharge characteristics of impure MgO with $SiO_2$ doped.

• 한국재료학회지
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• 제19권11호
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• pp.613-618
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• 2009

We designed new compositions for lead free and low temperature sealing glass frit of $ZnO-V_2O_5-P_2O_5$ system, which can be used for PDP (Plasma Display Panel) or other electronic devices. The $ZnO-V_2O_5-P_2O_5$ system can be used as a sealing material at temperatures even lower than 430$^{\circ}C$. This system, however, showed lower bonding strength with glass substrate compared to commercialized Pb based sealing materials. So, we added $TiO_2$ as a promoter for bonding strength. We examined the effect of $TiO_2$ addition on sealing behaviors of $ZnO-V_2O_5-P_2O_5$ glasses with the data for flow button, wetting angle, temporary & permanent residual stress of glass substrate, EPMA analysis of interface between sealing materials and glass substrate, and bonding strength. As a result, sealing characteristics of $ZnO-V_2O_5-P_2O_5$ system glasses were improved with $TiO_2$ addition, but showed a maximum value at 5 mol% $TiO_2$ addition. The reason for improved bonding characteristics was considered to be the chemical interaction between glass substrate and sealing glass, and structural densification of sealing glass itself.

• 한국수소및신에너지학회논문집
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• 제17권1호
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• pp.69-74
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• 2006

Thick film $H_2$ sensors were fabricated using $SnO_2$ loaded with $Ag_2O$ and $PtO_x$. The composition that gave the highest sensitivity for $H_2$ was in the weight% ratio of $SnO_2 : PtO_x : Ag_2O$ as 93 : 1 : 6. The nano-crystalline powders of $SnO_2$ synthesized by sol-gel method were screen printed with $Ag_2O$ and $PtO_x$ on alumina substrates. The fabricated sensors were tested against gases like $H_2$, $CH_4$, $C_3H_8$, $C_2H_5OH$ and $SO_2$. The composite material was found sensitive against $H_2$ at the working temperature $130^{\circ}C$, with minor interference of other gases. The $H_2$ gas as low as 100 ppm can be detected by the present fabricated sensors. It was found that the sensors based on $SnO_2-Ag_2O-PtO_x$ system exhibited the high performance, high selectivity and very short response time to $H_2$ at ppm level. These characteristics make the sensor to be a promising candidate for detecting low concentrations of $H_2$.

• 한국진공학회지
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• 제8권1호
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• pp.70-74
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• 1999

Plasma Display Panel(PDP)에서 보호막 물질로 사용중인 MgO 특성을 개선하기 위하여 본 연구에서는 MgO-CaO 박막을 전자빔 증착법으로 제조하였다. MgO 최대 증착속도는 1025 $\AA$/min이었으며 CaO 첨가비가 증가함에 따라 증착속도는 감소하였고, XRD 패턴은 전체적으로 낮은 2$\theta$각 방향으로 이동하였다. MgO 대한 CaO의 최대 고용도는 0.13이다. 최적전압특성을 나타낸 조성은 Mg 47.1 at%, Ca 1.3 at%, O 51.6 at%이었으며 이때 방전개시전압은 176 V, 메모리마진은 0.5였으며 증착속도는 515$\AA$/min이었다.

• 한국재료학회지
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• 제4권2호
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• pp.159-165
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• 1994

순수한 알루미늄을 양극산화한 $AI_2O_3/AI$ 소자 및 그 위에$SnO_2$를 증착, 소자를 제작하여 그들의 전기적인 특성을 여러 습도 분위기 중에서 조사하였다. 단위습도당의 표면저항 변화는 $AI_2O_3/AI$ 소자에서는 $1.40 \times 10^{-2}\Omega$ /RH이었다. 두 소자는 습도에 따른 표면저항 변화중에서 hysteresis현상을 나타내고 있지만, $SnO_2-AI_2O_3/Al$ 소자쪽이 더 작은 hysteresis현상을 나타내었다. $SnO_2-AI_2O_3/Al$ 소자에 있어서 표면저항에 대한 온도의존성은 40-$60^{\circ}C$에서 $2.50 \times 10^{-2} \Omega /^{\circ}C$인것에비해 0~$20^{\circ}C$에서는 $0.56 \times 10^{-2} \Omega /^{\circ}C$와 같이 적기 때문에 $SnO_2-AI_2O_3/Al$ 소자는 실온영역에서 습도센서로 쓸 수 있다고 결론할 수 있다.

• 공업화학
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• 제10권2호
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• pp.231-236
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• 1999

결정상과 분산도가 조절된 $MoO_3$/$SiO_2$ 담지촉매를 제조하여 촉매의 표면특성과 디벤조티오펜 탈황반응의 활성도를 고찰하였다. Mo의 표면담지량은 4 atoms $Mo/nm^2$이었으며, 실리카 표면 위에 형성된 $MoO_3$의 결정상은 sintered hexagonal, sintered orthorhombic, 및 dispersed hexagonal상이었다. XRD, Raman, 및 $O_2$ 흡착 결과 $MoO_3$의 표면분산도는 sintered hexagonal < sintered orthorhombic < dispersed hexagonal 순으로 증가하였다. TPR 결과 $MoO_3$ 결정은 $650^{\circ}C$에서 $MoO_2$로, $1000^{\circ}C$에서 Mo로 환원됨을 알 수 있었다. 디벤조티오펜 탈황반응을 30기압, $350{\sim}500^{\circ}C$ 온도범위에서 수행하였으며, 실험 결과 활성도는 $MoO_3$ 결정체의 $SiO_2$ 표면에서의 분산도에 비례하여 증가함을 알 수 있었다.

• 한국세라믹학회지
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• 제35권11호
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• pp.1130-1140
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• 1998

Thin films of $Bi_4Ti_3O_{12}\;nBaTiO_3(n=1&2)$ were prepared using sols erived Ba-Bi-Ti complex alkoxides. The sols were spin-cast onto $Pt/Ti/SiO_2/Si$ substrates and followed by pyrolysis for 1 hr at $620^{\circ}C,\;700^{\circ}C\;and\;750^{\circ}C$ In the thin films a pyrochlore phase seemed to be formed at a lower temperature and then tran-formed to the layered perovskite phase as the heating temperature increased. In the thin films pyrolyzed at formed to the layered perovskte phase as the heating temperature increased. In the films pyrolyzed at $750^{\circ}C$ the amount of $Bi_4Ti_3O_{12}{\cdot}BaTiO_3$ reached to 94% while $Bi_4Ti_3O_{12}{\cdot}BaTiO_3$ was 77% in composition. This result shows that the formation of the layered pervoskite phase becomes difficult as the amount of complexing $BaTiO_3$ increases. The microstructures and the electrical properties of the thin films were gen-erally improved with the incease of the heating temperature. However the presence of the pyrochlore phase could not be removed effectively. Our study showed that the electrical properties of $Bi_4Ti_3O_{12}{\cdot}BaTiO_3$ were pronouncedly improved with complexing with BaTiO3 when compared to those of $Bi_4Ti_3O_{12}$ while the presence of the pyrochlore phase was detrimental to the those of $Bi_4Ti_3O_{12}{\cdot}2BaTiO_3$.