• Bulletin of the Korean Chemical Society
• /
• 제35권3호
• /
• pp.925-928
• /
• 2014

A dye-sensitized solar cell (DSSC) was fabricated with a nanocrystalline $TiO_2$ film electrode on FTO glass, N719 dye, electrolytes (or $CsSnI_3$), and counter Pt electrode by incorporating it with single-walled carbon nanotubes (SWNTs). SWNTs were combined with $TiO_2$ film, $CsSnI_3$, Pt electrode, separately, and the SWNT-containing cell was compared with a pristine cell in cell performance. We also examined the performance change by pressing $TiO_2$ film, during cell fabrication, inside a high pressure chamber. Mostly, the change of conversion efficiency was compared for each cell, and an atomic force microscopy data were suggested to explain our results.

• 전기화학회지
• /
• 제9권2호
• /
• pp.59-63
• /
• 2006

전해코팅 법과 dip-coating 법을 이용해 산화주석(IV)을 티타늄 지지체에 코팅하여, 코팅 방법에 따른 코팅 전극의 물성과 전기화학적 특성에 대해여 연구하였다. HCl 로 전극 에칭 후, nitrate 용액에 $SnCl_2{\cdot}2H_2O$을 용해시켜 pulse technique를 이용하여 전해코팅 하였으며, dip-coating 법 또한 $SnCl_2{\cdot}2H_2O$를 사용하여 1:1V% HCl 용액에 용해시켜 코팅 소결 후 산화주석(IV)코팅 전극을 제작하였다. 두 가지 코팅 방법을 통해 제작된 산화주석(IV)코팅 전극은 전극의 물성을 비교하기 위해 x-ray diffraction (XRD), scanning election microscopy (SEM)를 관찰해보았고, 전기화학적 특성을 평가하기 위해 cyclic voltammetry (CV)를 측정하여 전위창을 비교해 보았다.

• 한국세라믹학회지
• /
• 제18권2호
• /
• pp.119-125
• /
• 1981

The thermostable resistor was made by using P.T.C.R-N.T.C.R. ceramics. In this study $BaTiO_3$ type P.T.C.R. ceramics and $SnO_2-Sb_2O_3$ type N.T.C.R. ceramics were cocrystallized in one body and electrical resistance was stable under the temperature variation between $25^{\circ}C$-40$0^{\circ}C$. The ceramics showed the most stable electrical resistance for the mal variation when the composition was 0.6P.T.C.R. $BaTiO_3$,$ 0.4SnO_2$ and 0.01 $Sb_2O_3$.

• 한국세라믹학회지
• /
• 제50권1호
• /
• pp.87-91
• /
• 2013

The doping effect of Sn on the microstructure evolution and dielectric properties was studied in $CaCu_3Ti_{4-x}Sn_xO_{12}$ polycrystals. Samples were produced by a conventional solid-state reaction method. Sintering was carried out at $1115^{\circ}C$ for 2-16 h in air. The dielectric constant and loss were examined at room temperature over a frequency range between $10^2$ and $10^6$ Hz. The microstructure was found to evolve into three stages. Addition of $SnO_2$ led to an increase in density and advanced formation of abnormal grains. The formation of coarse grains with a reduced thickness of the boundary brought about an enhanced dielectric constant and a lower dielectric loss below ~1 kHz. EDS data showed the Cu-rich phase along the grain boundary, which should contribute to the improved dielectric constant according to the internal barrier layer capacitor model. After all, $SnO_2$ was an effective dopant to elevate the dielectric characteristics of $CaCu_3Ti_{4-x}Sn_xO_{12}$ polycrystals as a promoter for abnormal grain growth.

• 자원환경지질
• /
• 제28권1호
• /
• pp.33-41
• /
• 1995

Tin mineralizations in South Korea have been found only in the Ulchin and the Sangdong areas. The Wangpiri and the Yuchang Sn pegmatites appear to be in close spatial and genetical relation to the Wangpiri granitoid in the Ulchin area, and the Soonkyeong Sn pegmatite be in close association with the Nonggeori granites in the Sangdong area from geochemical viewpoint. The electron-microprobe analysis of muscovite, biotite, tourmaline and cassiterite from the granitoids and pegmatites in the Ulchin and the Sangdong areas has revealed a distinct differences of geochemical compositions. The Wangpiri and the Yuchang Sn pegmatites show an enrichment of MnO and a depletion of $TiO_2$, FeO and MgO in comparison with the Soonkyeong Sn pegmatite. This result coincides with the geochemical compositions of granitoid rocks in these areas. Enrichment of MnO and depletion of $TiO_2$ FeO and MgO are characteristic in muscovite, biotite and tourmaline of pegmatites compared with those of granitoids. These geochemical differences of muscovite, biotite and tourmaline between granitoids and pegmatites in these areas implies that pegmatites are more fractionated than granitoids.

• 한국결정성장학회지
• /
• 제19권5호
• /
• pp.256-261
• /
• 2009

Sol-gel법에 의해 친수성 투명 $TiO_2$ 박막이 제조되었고, 박막의 접촉각, 표면구조, 투과율의 특성이 측정되었다. 더욱이 박막의 친수 특성을 향상시키기 위하여 계면활성제 tween 80이 이용되었다. Tween 80의 첨가량이 0, 10, 30, 50wt%일 때, 제조된 박막의 접촉각은 각각 $41.4^{\circ}$, $18.2^{\circ}$, $16.0^{\circ}$, $13.2^{\circ}$로 확인되었다. 제조된 $TiO_2$ 박막은 자외선 조사 후 Methylene blue용액을 분해시켜 흡광도를 감소시키는 광촉매 특성을 보여주었다. 일반유리(bare glass), Antimony Tin Oxide(ATO)코팅 유리, Fluorine Tin Oxide(FTO)코팅유리, Indium Tin Oxide(ITO)코팅유리 기판 위 에 Tween 80을 30 wt% 함유한 $TiO_2$ 용액을 적층하여 박막의 접촉각과 투과율을 측정하였다. 다양한 기판에 제조된 박막은 $16.2\sim27.1^{\circ}$의 표면 접촉각을 나타냈으며 자외선 조사 후에는 접촉각이 $13.2\sim17.6^{\circ}$로 낮아졌다. 특히 ATO코팅유리와 FTO 코팅유리 기판 위에 코팅된 필름은 가시광선 영역에서 각각 74.6%, 76.8%의 높은 투과율을 나타내었고, 적외선 영역에서는 각각 54.2%, 40.4%의 낮은 투과율을 나타냈다.

• 센서학회지
• /
• 제9권3호
• /
• pp.242-247
• /
• 2000

10 mole%의 과잉 PbO가 첨가된 타겟을 이용하여 $(La_{0.5}Sr_{0.5})CoO_3(LSCO)/Pt/Ti/SiO_2/Si$ 위에 RF 마그네트론 스퍼터링 방법을 이용하여 $Pb_{0.99}[(Zr_{0.6}Sn_{0.4})_{0.9}Ti_{0.1}]_{0.98}Nb_{0.02}O_3(PNZST)$ 박막을 증착시켰다. $500^{\circ}C$의 기판온도, 80W의 RF power에서 증착된 박막은 급속열처리(RTA)후에 페로브스카이트 상으로 결정화되었다. $650^{\circ}C$, 공기중에서 10초 동안 열처리된 박막이 가장 우수한 결정성과 전기적 특성을 나타내었다. 이러한 박막으로 제작된 PNZST 커패시터는 약 $20\;{\mu}C/cm^2$ 정도의 잔류분극과 약 50 kV/cm 정도의 항전계를 나타내었다. 또한, $2.2{\times}10^9$의 스위칭 후에도 잔류분극의 감소는 10% 미만이었다.

• 센서학회지
• /
• 제21권6호
• /
• pp.395-401
• /
• 2012

The bond strength of three types of $TiO_2$ coatings onto fluorine-doped $SnO_2$ (FTO) glass was investigated with the aid of a tape test according to ASTM D 3359-95. Transmittance was then measured using an UV-vis spectrophotometer in the wavelength range of 300 nm to 800 nm to evaluate the extent of adhesion of $TiO_2$ nanorods/nanoparticles on FTO glass. A sharp interface between the coating layer and the substrate was observed for single $TiO_2$ coating ($TiO_2$ nanorods/FTO glass), which may be detrimental to the bonding strength. In multicoating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/$TiO_2$ nanoparticle/FTO glass), the tape test was not performed due to severe peeling-off prior to the test. On the other hand, the dual coating sample ($TiO_2$ nanorod/$TiO_2$ nanoparticle/FTO glass) showed minimum variation of transmittance (4%) after the test, suggesting that the topcoat adheres well with the FTO substrate due to the presence of the $TiO_2$ nanoparticle buffer layer. The use of a $TiO_2$ nanorod electrode layer with good adhesion may be attributed to the excellent dye sensitized solar cell performance.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.591-592
• /
• 2005

PTC Thermistors specimens were fabricated by added $MnO_2$ as donors, and $Nb_2O_5$ as acceptors and sintered $1250^{\circ}C$/2hrs. Average grain size decreased with increased in added $MnO_2$, and increased with added in $Nb_2O_5$. But, appeared liquid phase as $Bi_2O_3$ and $TiO_2$, affect to grain growth. XRD result, peak strength waslowed then crystallization not well, but, secondary phase were not showed all specimens. All specimens resistance were so high, about $40M\Omega$ over, couldn't measured to those resistance and doesn't appear PTCR effect.

• The Korean Journal of Ceramics
• /
• 제2권3호
• /
• pp.162-166
• /
• 1996

The effects of NiO addition on the microstructure and microwave dielectric properties of ($Zr_{08}Sn_{02}$)$TiO_4$ (ZST) were investigated. With the NiO addition, a higher density of ZST ceramics than 95% of the theoretical values has been obtained in the sintering temperature range of 1400 to 150$0^{\circ}C$. Energy dispersive X-ray spectrometry (EDS) analysis of sintered specimen shows the presence of second phase at grain boundaries, which is considered to be $NiTiO_3$. Dielectric constant of the specimen is found to increase linearly with density. Q-values and TC$_r$ decrease with increasing NiO content. The variation of dielectric properties with NiO content is discussed in terms of the second phase. The ZST ceramics with 0.25 wt% NiO showed ${\varepsilon}_{\gamma}$=38, Q=7000 at GHz and TC$\gamma$=-0.5 ppm/$^{\circ}C$, comparable with the values obtained by the previous investigations.