• Bulletin of the Korean Chemical Society
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• 제19권1호
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• pp.107-109
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• 1998

The $SnO_2$, Sn-doped $In_2O+3\; and \;Ce-doped\; TiO_2$ films have been prepared by RF sputtering method, and their opto-electrochemical properties were investigated in view of the applicability as counter electrodes in the electrochromic window system. These oxide films could reversibly intercalate $Li^+$ ions owing to the nanocrystalline texture, but remained colorless and transparent. The high transmittance of the lithiated films could be attributed to the prevalence of the $Sn^{4+}/Sn^{2+}\; and\; Ce^{4+}/Ce^{3+}$ redox couples having 5s and 6s character conduction bands, respectively. For the Ce-doped $TiO_2$ film, $(TiO_2)_{1-x}(CeO_2)_x$, an optimized electrochemical reversibility was found in the film with the composition of x = 0.1.

• 한국결정성장학회지
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• 제13권5호
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• pp.241-246
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• 2003

ATO(antimony-doped tin oxide) 투명전도막을 sol-gel dip coating 방법에 의해 $SiO_2$/glass 기판 위에 성공적으로 제조하였다 ATO막의 결정상은 $SnO_2$상임을 확인하였고, 막의 두께는 withdrawal speed를 50 mm/minute로 코팅시 약 100 nm/layer였다. $SiO_2$/glass 기판 위에 코팅한 400 nm두께의 ATO 박막을 질소분위기에서 annealing한 후, 측정한 광 투과율과 전기 저항치는 각각 84%와 $5.0\times 10^{-3}\Omega \textrm{cm}$였다. 이러한 특성은 $SiO_2$막이 Na 이온의 확산을 제어하여 $Na_2SnO_3$ 및 SnO와 같은 불순물의 형성을 억제하고, 막 내부의 Sb의 농도와 $Sb^{3+}$에 대한 $Sb^{5+}$의 비를 증가시키는데 기여했기 때문으로 확인되었다. 또한, $N_2$ annealing은 $Sb^{5+}$뿐만 아니라 $Sn^{4+}$를 환원시킴으로써 전기전도도를 향상시킴을 확인하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제15권4호
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• pp.15-20
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• 2013

We investigated the flux pinning properties of both 10 mol% Zr-and Sn-doped $YBa_2Cu_3O_{7-{\delta}}$ (YBCO) films with the same thickness of ~350 nm for a comparative purpose. The films were prepared on the $SrTiO_3$ (STO) single crystal substrate by the metal-organic deposition (MOD) process. Compared with Sn-doped YBCO film, Zr-doped one exhibited a significant enhancement in the critical current density ($J_c$) and pinning force density ($F_p$). The anisotropic $J_{c,min}/J_{c,max}$ ratio in the field-angle dependence of $J_c$ at 77 K for 1 T was also improved from 0.23 for Sn-doped YBCO to 0.39 for Zr-doped YBCO. Thus, the highest magnetic $J_c$ values of 9.0 and $2.9MA/cm^2$ with the maximum $F_p$ ($F_{p,max}$) values of 19 and $5GN/m^3$ at 65 and 77 K for H // c, respectively, could be achieved from Zr-doped YBCO film. The stronger pinning effect in Zr-doped YBCO film is attributable to smaller $BaZrO_3$ (BZO) nanoparticles (the average size ${\approx}28.4$ nm) than $YBa_2SnO_{5.5}$ (YBSO) nanoparticles (the average size ${\approx}45.0$ nm) incorporated in Sn-doped YBCO film since smaller nanoparticles can generate more defects acting as effective flux pinning sites due to larger incoherent interfacial area for the same doping concentration.

• 한국결정성장학회지
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• 제31권4호
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• pp.154-158
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• 2021

550 nm 파장대에서 O₂/Ar+O₂ 혼합기체 농도비가 0에서 7.9 %로 변화 시 Mn 도핑된 SnO₂ 투명전도막의 투과율은 80.9에서 85.4 %로 밴드갭 에너지는 3.0에서 3.6 eV로 증가하였다. 비저항은 O₂/Ar+O₂ 혼합기체 농도비가 0에서 2.7 %까지 증가 시 3.21 Ω·cm에서 0.03 Ω·cm으로 감소하다 이후 7.9 %로 증가 시에는, 52.0 Ω·cm으로 급격하게 상승하였다. XPS 분석결과 혼합기체 O₂/Ar+O₂에서 O₂ 농도의 증가로 Sn_3d5/2의 결합에너지가 486.40에서 486.58 eV로, O_1s의 결합에너지도 530.20에서 530.34 eV로 조금 변화하였다. 따라서 스파터링 방법으로 제조한 Mn 도핑된 SnO₂ 투명전도막에서 O₂ 농도변화에 따라 SnO와 SnO₂ 2개의 상이 공존하는 것을 확인하였다.

• 한국전기전자재료학회논문지
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• 제23권12호
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• pp.956-960
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• 2010

CuO doped $WO_3-SnO_2$ thick film gas sensors were fabricated by screen printing method on alumina substrates and heat-treated at $350^{\circ}C$ in air. The effects of mixing ratio of $WO_3$ with $SnO_2$ on the structural and morphological properties of $WO_3-SnO_2$ were investigated X-ray diffraction and Scanning Electron Microscope. The structural properties of the $WO_3-SnO_2$:CuO thick film by XRD showed that the monoclinic of $WO_3$ and the tetragonal of $SnO_2$ phase were mixed. Nano CuO was coated on the $WO_3-SnO_2$ surface and then the surface of $WO_3$ was coated with $SnO_2$ particles with $1\sim1.5{\mu}m$ in diameters, as confirmed form the SEM image. The sensitivity of the $WO_3-SnO_2$:CuO sensor to 2000 ppm $CO_2$ gas and 50 ppm $H_2S$ gas for the various ratio of $WO_3$ and $SnO_2$ was investigated. The 4 wt% CuO doped $WO_3-SnO_2$(75:25) tkick films showed the highest sensitivity to $CO_2$ gas and $H_2S$ gas.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.99-102
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• 1997

An electronic nose system is an instrument designed far mimicking human olfactory system. It consists generally of gas (odor) sensor array corresponding to olfactory receptors of human nose and artificial neural network pattern recognition technique based on human biological odor sensing mechanism. Considerable attempts to develop the electronic nose system have been made far applications in the fields of floods, drinks, cosmetics, environment monitoring, etc. A portable electronic nose system has been fabricated by using oxide semiconductor gas sensor array and pattern recognition technique such as principal component analysis (PCA) and back propagation artificial neural network The sensor array consists of six thick film gas sensors whose sensing layers are Pd-doped WO$_3$ Pt-doped SnO$_2$ TiO$_2$-Sb$_2$O$_3$-Pd-doped SnO$_2$ TiO$_2$-Sb$_2$O$_{5}$-Pd-doped SnO$_2$+Pd filter layer, A1$_2$O$_3$-doped ZnO and PdCl$_2$-doped SnO$_2$. As an application the system has been used to identify CO/HC car exhausting gases and the identification has been successfully demonstrated.d.

• 한국세라믹학회지
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• 제23권3호
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• pp.53-61
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• 1986

A gas sensor which has been made by wet process had fabricated by coating each of the mixture on alumina tube and firing at 85$0^{\circ}C$ for 3hrs. A gas concentration such $H_2$, CO, $C_3H_8$, $C_2H_2$ and $CH_4$ vs its detection voltage characteristics has been in-vestigated on $SnO_2-In_2O_3-MgO$ system doped with PdO, $La_2O_3$, $ThO_2$, NiO and $Nb_2O_5$ The optimum sensitivity composition for various gases were 90w/o $SnO_2$-9w/o $In_2O_3$-1w/o MgO for $H_2$, $C_2H_2$ CO and $C_3H_8$ and 95w/o $SnO_2$-4w/o $In_2O_3$-1w/o MgO for $CH_4$. The sample which has been made by wet process than dry process had predominated sensitivity for each gases and particle size of the sample coprecipitated with PH=9 was 0.1${\mu}{\textrm}{m}$ The $SnO_2$-In2_O_3-MgO$ system doped with 2w/o $Nb_2O_5$ and NiO was the most sensitive for $H_2$ and $C_2H_2$ gas. In $SnO_2$-In2_O_3-MgO$ system doped with $ThO_2$ the sensitivity of $H_2$ gas was decreased but CO gas was in-creased when dopant con was increased.

• 한국전기전자재료학회논문지
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• 제37권5호
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• pp.500-506
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• 2024

The transparent electrode characteristics of the SnO₂/AgNi/SnO₂ (OMO) multilayer structures prepared by sputtering were investigated according to the annealing temperature. Ni-doped Ag of various compositions was selected as the metal layer and heat treatment was performed at 100~300℃ to evaluate the thermal stability of the metals. The manufactured OMO multilayer structures were heat treated for 6 hours at 400~600℃ in an N₂ atmosphere. The structural, electrical, and optical properties of the OMO structures before and after annealing were evaluated and analyzed using a UV-VIS spectrophotometer, 4-point probe, XPS, FE-SEM, etc. OMO with Ni-doped Ag shows improved performance due to the reduction of structural defects of Ag during annealing, but OMO structure with pure Ag shows degradation characteristics due to Ag diffusion into the oxide layer during high-temperature annealing. The figure of merit (FOM) of SnO₂/Ag/SnO₂ was highest at room temperature and gradually decreased as the heat treatment temperature increased. On the other hand, the FOM value of SnO₂/AgNi/SnO₂ mostly showed its maximum value at high temperature(~550℃). In particular, the FOM value of SnO₂/Ag-Ni (3.2 at%)/SnO₂ was estimated to be approximately 2.38×10^-2 Ω^-1. Compared to transparent electrodes made of other similar materials, the FOM value of the SnO₂/Ag-Ni (3.2 at%)/SnO₂ multilayer structure is competitive and is expected to be used as an alternative transparent conductive electrode in various devices.

• 한국세라믹학회지
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• 제51권1호
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• pp.43-50
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• 2014

We fabricated undoped and Sb-doped $SnO_2$ thin films on glass substrates by a pulsed laser deposition (PLD) process. Undoped and 2 - 8 wt% $Sb_2O_3$-doped $SnO_2$ targets with a high density level of ~90% were prepared by the spark plasma sintering (SPS) process. Initially, the effects of the deposition temperature on undoped $SnO_2$ thin films were investigated in the region of $100-600^{\circ}C$. While the undoped $SnO_2$ film exhibited the lowest resistivity of $1.20{\times}10^{-2}{\Omega}{\cdot}cm$ at $200^{\circ}C$ due to the highest carrier concentration generated by the oxygen vacancies, 2 wt% Sb-doped $SnO_2$ film exhibited the lowest resistivity value of $5.43{\times}10^{-3}{\Omega}{\cdot}cm$, the highest average transmittance of 85.8%, and the highest figure of merit of 1202 ${\Omega}^{-1}{\cdot}cm^{-1}$ at $400^{\circ}C$ among all of the doped films. These results imply that 2 wt% $Sb_2O_3$ is an optimum doping content close to the solubility limit of $Sb^{5+}$ substitution for the $Sb^{4+}$ sites of $SnO_2$.

• 한국재료학회지
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• 제18권4호
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• pp.193-198
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• 2008

$WO_3$-doped $SnO_2$ thin films were prepared in a solution-deposition method and their gas-sensing characteristics were investigated. The doping of $WO_3$ to $SnO_2$ increased the response ($R_a/R_g,\;R_a$: resistance in air, $R_g$: resistance in gas) to $H_2$ substantially. Moreover, the $R_a/R_g$ value of 10 ppm CO increased to 5.65, whereas that of $NO_2$ did not change by a significant amount. The enhanced response to $H_2$ and the selective detection of CO in the presence of $NO_2$ were explained in relation to the change in the surface reaction by the addition of $WO_3$. The $WO_3$-doped $SnO_2$ sensor can be used with the application of a $H_2$ sensor for vehicles that utilize fuel cells and as an air quality sensor to detect CO-containing exhaust gases emitted from gasoline engines.