• Journal of the Korean Ceramic Society
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• v.39 no.4
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• pp.386-393
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• 2002

Fabricatio of the potassium-titanate fiber with K2O${\cdot}nTiO_2$ composition and coating of electrically conductive Sb-doped $SnO_2$ (ATO: Antimony Tin Oxide) layer on the fiber on the fiber were the fiber were the aims of this work. The fiber fabricated by slow-cooling technique showed the mean length of $15{\mu}m$ and mean diameter of $0.5{\mu}m$. Three different coating methods i.e, sol-gel, co-precipitation and urea technique, were attempted to coat the conductive ATO layer on the potassium-titanate fiber. The influences of coating method, concentrations of ATO(5∼70wt%) and Sb (0∼20wt%), temperature in the range of $450\;to\;800^{\circ}C$, number of washing (3∼4 times) on the resistivity of the ATO coated fiber were examined in details. The fiber coated ATO by coprecipitation exhibited lower resistivity of 103${\Omega}{\cdot}$cm at the 30 wt% of ATO, and showed nearly constant low value of $60{\Omega}{\cdot}cm\;to\;90{\Omega}{\cdot}$cm at the higher concentration of ATO.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.71-71
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• 2003

최근 통신용 전자부품의 소형화, 저가격화, 고기능화의 요구가 점점 더 증대되고 있으며 이를 위해서 기판의 배선밀도를 높이는 것과 개별 부품 또는 모듈의 크기와 무게를 줄이는 것이 절실히 필요하다. 본 연구에서는 저융점의 phosphate계 유리 프릿의 첨가를 통해 LTCC (Low Temperature Co-fired Ceramic) 에 적용 가능한 조성을 개발하고자 하였다. 마이크로파 용 유전재료로서 널리 사용되고있는 BNT (BaO-Nd$_2$O$_3$-TiO$_3$) 계 세라믹스에 저융점 유리 프릿의 양을 10-30wt% 범위로 변화시키면서 900-110$0^{\circ}C$ 범위에서 소결하여 이에 따른 수축률 변화와 상대밀도의 변화를 조사하였다 유리 프릿으로 P$_2$O$_{5}$-ZnO-BaO-Nd$_2$O$_3$ 계, P$_2$O$_{5}$-SnO-ZnO 계 2가지 조성의 유리를 사용하였다 그 결과로 소결체의 상대밀도는 소성온도가 900-110$0^{\circ}C$ 로 증가함에 따라 85-96% 로 증가하였고, 그 수축률은 소결온도 100$0^{\circ}C$ 에서 급격히 증가하였다. 이러한 결과는 저온 동시소성 세라믹 조성의 사용을 위해 좋은 결과가 예상된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.543-543
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• 2013

Thin-film transistors (TFTs) based on oxide semiconductors have been regarded as promising alternatives for conventional amorphous and polycrystalline silicon TFTs. Oxide TFTs have several advantages, such as low temperature processing, transparency and high field-effect mobility. Lots of oxide semiconductors for example ZnO, SnO2, In2O3, InZnO, ZnSnO, and InGaZnO etc. have been researched. Particularly, zinc-tin oxide (ZTO) is suitable for channel layer of oxide TFTs having a high mobility that Sn in ZTO can improve the carrier transport by overlapping orbital. However, some issues related to the ZTO TFT electrical performance still remain to be resolved, such as obtaining good electrical contact between source/drain (S/D) electrodes and active channel layer. In this study, the bottom-gate type ZTO TFTs with staggered structure were prepared. Thin films of ZTO (40 nm thick) were deposited by DC magnetron sputtering and performed at room temperature in an Ar atmosphere with an oxygen partial pressure of 10%. After annealing the thin films of ZTO at $400^{\circ}C$ or an hour, Cu, Mo, ITO and Ti electrodes were used for the S/D electrodes. Cu, Mo, ITO and Ti (200 nm thick) were also deposited by DC magnetron sputtering at room temperature. The channel layer and S/D electrodes were defined using a lift-off process which resulted in a fixed width W of 100 ${\mu}m$ and channel length L varied from 10 to 50 ${\mu}m$. The TFT source/drain series resistance, the intrinsic mobility (${\mu}i$), and intrinsic threshold voltage (Vi) were extracted by transmission line method (TLM) using a series of TFTs with different channel lengths. And the performances of ZTO TFTs were measured by using HP 4145B semiconductor analyzer. The results showed that the Cu S/D electrodes had a high intrinsic field effect mobility and a low effective contact resistance compared to other electrodes such as Mo, ITO and Ti.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.15-18
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• 2014

We present gas sensing performance based on $2{\times}2$ sensor array with four different elements ($TiO_2$, $SnO_2$, $WO_3$ and $In_2O_3$ thin films) fabricated by rf sputter. Each thin film was deposited onto the selected $SiO_2$/Si substrate with Pt interdigitated electrodes (IDEs) of $5{\mu}m$ spacing which were fabricated on a $SiO_2$/Si substrate using photolithography and dry etching. For 5 ppm $NO_2$ and 50 ppm CO, each thin film sensor has a different response to offers the distinguishable response pattern for different gas molecules. Compared with the conventional micro-fabrication technology, $2{\times}2$ sensor array with such remarkable response pattern will be open a new foundation for monolithic integration of high-performance chemoresistive sensors with simplicity in fabrication, low cost, high reliablity, and multifunctional smart sensors for environmental monitoring.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.447-447
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• 2008

본 논문의 목표는 염료감응 태양전지의 재료적 특성중 반사율을 측정하여 가장 투명한 dye sensitized solar cell을 제조하기 위한 기초자료를 도출하기 위함이다. 먼저 염료감응 태양전지의 재료중 산화물질인 TiO2,SnO2,ZnO,$Nb_2O_5$ 10~50nm두께로 ITO 기판위에 코팅하여 UV-VIS를 통해 파장별 반사 특성을 분석하였다. 또한, 동일한 시료를 사용하여 FESEM을 통한 표면 Morphology를 확인하였다. 기판제료인 TiO2,dye(염료),TCO,glass,ICO 에 대해서도 동일한 특성분석을 하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.81-87
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• 2004

Semiconductor thick film gas sensors based on tin oxide are fabricated and their gas response characteristics are examined for four simulant gases of chemical warfare agent (CWA)s. The sensing materials are prepared in three different sets. 1) The Pt or Pd $(1,\;2,\;3\;wt.\%)$ as catalyst is impregnated in the base material of $SnO_2$ by impregnation method.2) $Al_2O_3\;(0,\;4,\;12,\;20\;wt.\%),\;In_2O_3\;(1,\;2,\;3\;wt.\%),\;WO_3\;(1,\;2,\;3\;wt.\%),\;TiO_2\;(3,\;5,\;10\;wt.\%)$ or $SiO_2\;(3,\;5,\;10\;wt.\%)$ is added to $SnO_2$ by physical ball milling process. 3) ZnO $(1,\;2,\;3,\;4,\;5\;wt.\%)$ or $ZrO_2\;(1,\;3,\;5\;wt.\%)$ is added to $SnO_2$ by co-precipitation method. Surface morphology, particle size, and specific surface area of fabricated sensing films are performed by the SEM, XRD and BET respectively. Response characteristics are examined for simulant gases with temperature in the range 200 to $400^{\circ}C$, with different gas concentrations. These sensors have high sensitivities more than $50\%$ at 500ppb concentration for test gases and also have shown good repetition tests. Four sensing materials are selected with good sensitivity and stability and are fabricated as a sensor array A sensor array Identities among the four simulant gases through the principal component analysis (PCA). High sensitivity is acquired by using the semiconductor thick film gas sensors and four CWA gases are classified by using a sensor array through PCA.

• Journal of the Korean Ceramic Society
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• v.48 no.1
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• pp.94-98
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• 2011

A Sn-doped $In_2O_3$ (ITO) nanowire photoelectrode was produced using a simple metal evaporation method at low synthesis temperature (< $540^{\circ}C$). The nanowire electrodes have large surface area compared with that of flat ITO thin film, and show low electrical resistivity of $5.6{\times}10^{-3}{\Omega}cm$ at room temperature. In order to apply ITO nanowires to the photoelectrodes of dye-sensitized solar cell (DSSC), those surfaces were modified by $TiO_2$ nanoparticles using a chemical bath deposition (CBD) method. The conversion efficiency of the fabricated $TiO_2$/ITO nanostructure-based DSSC was obtained at 1.4%, which was increased value by a factor of 6 than one without ITO nanowires photoelectrode. This result is attributed to the large surface area and superior electrical property of the ITO nanowires photoelectrode, as well as the structural advantages, including short diffusion length of photo-induced electrons, of the fabricated $TiO_2$/ITO nanostructure-based DSSC.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.482-487
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• 2008

성능이 우수한 다성분계 전극을 개발하기 위하여 Ru를 주 전극성분으로 Pt, Sn, Sb 및 Gd를 보조 전극성분으로 하여 3, 4성분계 전극의 성능과 산화제 생성량 및 전극 표면 분석을 행하여 다음의 결과를 얻었다. 1. 2분 동안 단위 W당 제거된 RhB 농토는 Ru:Sn:Sb=9:1:1 > Ru:Pt:Gd=5:5:1 > Ru:Sn=9:1 > Ru:Sn:Gd=9:1:1 > Ru:Sb:Gd=9:1:1로 나타났다. Ru:Sn:Sb=9:1.1 전극에서 발생하는 free Cl, ClO$_2$ 및 H$_2$O$_2$농도가 다른 전극보다 높은 것으로 나타나 산화제 생성경향과 RhB 분해율과는 상관관계가 있는 것으로 사료되었다. 4성분계 전극 중에서 Ru:Sn:Sb:Gd 전극의 성능이 가장 우수한 것으로 나타났으나 3성분계 전극인 Ru:Sn:Sb=9:1.1 전극보다 성능이 떨어지는 것으로 나타났다. Ru:Sn:Sb=9:1:1 전극에서 생성되는 산화제 농도가 다른 두 종류의 산화제 농도보다 높은 것으로 나타났고 4성분 전극의 경우 Ru:Sn:Sb:Gd 전극의 산화제 농도가 Ru:Sn:Sb:Gd 전극이 높거나 유사한 경우로 나타나 산화제 생성 경향과 RhB분해 능과는 상관관계가 있는 것으로 나타났다. 초기 RhB 분해 속도가 높은 전극의 COD 제거율도 높은 것으로 나타났다. OH 라디칼은 발생하지 않지만 염소계 산화제 농도가 높고 RhB제거율이 높아 Ru를 주 성분으로 한 전극의 RhB분해는 주로 간접 산화작용에 의한 것이며, 개발된 3, 4성분계 산화물 전극은 간접 산화용 전극임을 알 수 있었다. 에칭을 하기 전의 Ti판은 표면이 매끄러운 것으로 나타났으며, 35% 염산으로 에칭한 후의 Ti메쉬는 매우 거친 표면조직을 가지는 것을 관찰할 수 있었다. Ru:Sn:Sb=9:1:1 전극과 Ru:Sn:Sb:Gd 전극의 SEM 사진을 관찰한 결과 두 전극 모두 전극 물질이 균일하게 도포되어 있었으며, 두 전극 모두 열소성을 통해 전극 성분을 코팅할 때 발생하는 "mud crack"이 발생한 것이 관찰되었다 EDX 분석에서 Cl이 관찰되었는데, 전극 성분의 불완전 산화로 인한 비양론적 산화물 때문이며 이는 RhB 분해성능과 관련 있는 것으로 사료되었다.

• Journal of the Korean Ceramic Society
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• v.40 no.4
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• pp.360-364
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• 2003

Effects of sintering time upon the structures and microwave dielectric characteristics of co-substituted $Ba_{6-3x}$/S $m_{8+}$2x/ $Ti_{18}$ $O_{54}$ ceramics (x=2/3) were investigated. Prolonged sintering had significant effects upon the qf value and temperature coefficient, and a high Qf value (10,600 GHz) was obtained in the present ceramics combined with high-$\varepsilon$ (80) and near-zero temperature coefficient.t..

• International Journal of Computer Science & Network Security
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• v.24 no.10
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• pp.164-168
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• 2024

A dye-sensitized solar cell (DSSC) with a nanocrystalline TiO₂ film electrode on ITO glass, N719 dye, CsSnI₃ as solid state electrolyte to solve constancy problems such as electrode corrosion and electrolyte permeation, and counter WO₃ electrode, designed and simulated by wxAmps software. As research results has proved, that select graphene as 2D bridges into the nanocrystalline electrodes of dye-sensitized solar cells, which brought a faster electron transport and a lower recombination, together with a higher light scattering³. Compared to 1D nanomaterials and liquid electrolytes using in typical DSSCs, this simulation's results show more excellent properties and energy conversion efficiency (20.7102%).