알카리 금속 탄산염과 결착제의 혼합물을 감지물질로 하는 고체전해질 가스센서의 CO2 감응 특성

채유석,송갑득,강봉휘,서무교,이덕동 ( Yu Sug Chai,Kap Duk Song,Bong Hwi Kang,Moo Gyo Seo,Duk Dong Lee ) 한국센서학회 1998 센서학회지 Vol.7 No.2

The simple solid electrolyte carbon dioxide sensor with heaters were fabricated by using Li ionic conductor. Two Au electrodes were used for the reference and sensing electrode respectively. Two types of gas sensors, type ( I ) and type ( II ), were fabricated. Type ( I ) sensor was fabricated by the method of melting and crystallizing alkali metal carbonate at the temperature of 420 ∼ 500 ℃. The sensing membrane of type ( II ) sensor was formed by the printing method on sensing electrode after metal carbonate was mixed with binder. The response characteristics of sensors fabricated for the carbon dioxide were investigated for a range of CO₂ concentration from 950 ppm to 9,950 ppm at operating temperature 420 ℃. Type ( I ) sensor and type ( II ) sensor showed the sensitivity of 62 mV/decade and 65 mV/decade respectively. The emf/decade of type ( II ) sensor tested at 420 ℃ almost followed the theoretical value of Nernst`s equation and showed stable response characteristics with the fast response time of 15 ∼ 20 sec. Also type ( II ) sensor showed excellent stability and reproduction properties for 60 days.

CaO를 첨가한 Na고체전해질 센서의 CO₂가스 감도향상에 관한 연구

곽종식,서무교,최순돈,이덕동,Kwak, Jong-Sig,Seo, Moo-Gyo,Choi, Soon-Don,Lee, Duk-Dong 한국센서학회 2002 센서학회지 Vol.11 No.4

$CO_2$ 가스 감도를 높임과 동시에 감지거동을 안정화시키기 위하여 여러 함량의 CaO가 함유된 NASICON 전해질을 낮은 온도에서 소결하여 NASICON 센서를 제작하였다. 제조된 소자는 비교적 낮은 동작온도인 $250^{\circ}C$정도에서도 양호한 감도와 안정된 출력특성을 나타내었다. NASICON sensors that the NASICON electrolytes with various CaO amounts were sintered at low temperature($900^{\circ}C$), were fabricated to improve $CO_2$ sensitivity and stability in sensing behaviors. The manufactured device was shown good sensing characteristics and stability of output electromotive force at $250^{\circ}C$, comparatively low operating temperature.

Sol - Gel 법에 의한 Li 이온 - 고체 전해질의 CO2 가스 감지 특성

서무교,송갑득,곽종식,이덕동 ( Moo Gyo Seo,Kap Duk Song,jong Sik Kwak,Duk Dong Lee ) 한국센서학회 1995 센서학회지 Vol.4 No.3

Lithium ionic aolid electrclye was synthesized m in ambiencely sol-ge methxl. using tetraethyl orthosilcate, lithium metluwide, zirccmium n-prntxwide. utd trilntlle phosphate as precursors. he prepared material ryas dried and rmshed into ponder, nncl it w ns pressed into disk yux samples. $quot;These samples wcc sintemd at 0-C -11(X) fc () hours. The ply-sical characteristics of the samples acre imestigatecl ly TG D$quot; and lil) methods. CO senscn lrised on lithium ionic acdid elechwlye was fuhricated and its opxerationol characteristics were ntcsutrd. The sensing characteristics of the sensco sintered at 1(K) l show s the variation of e.m.f. OonU a.i Ei m\ decade fc the variaticm CO concentraticm at 0(l -ON) C efcerating temtxature. and goc linearit for 300-(i000 ppm.

고체전해질형 CO₂가스 감지 소자의 제작 및 그 동작 특성

서무교,송갑득,곽종식,이덕동 경북대학교 센서기술연구소 1994 센서技術學術大會論文集 Vol.5 No.1

The raw material of solid electrolyte type CO_(2) sensor was synthesized using tetraethoxysilane, lithium methoxide, zirconium n-propoxide, and tributyle phosphate as precursors, this process was carried out at 60℃ in N_(2) ambience. The prepared material was dried and crushed into powder, and it was pressed into disk type samples. These samples were sintered at 9000 -1100℃ for 50 hours. The physical characteristics of the samples were investigated by TG/DTA, SEM and XRD. The solid electrolyte type CO_(2) sensor was fabricated and its operational characteristics were measured. The sensing characteristics of the sensor shows about 86 mV/decade for the variation of CO_(2) concentration.

리티움 이온 전도체를 이용한 CO2 센서의 제조 및 그 특성

이덕동,서무교,송갑득 경북대학교 전자기술연구소 1996 電子技術硏究誌 Vol.17 No.1

Carbon dioxide gas sensor, which has inner heater, was fabricated using Li ionic conductor as raw material which was synthesized by sol-gel method. It had either Au electrode or Pt electrode as the metal electrode of sensing electrode part, and carbonate mixture was used as sensing electrode material of low operating temperature about 250℃. Sensing characteristics to carbon dioxide gas, and interference to carbon monoxide gas and hydro carbon gases were investigated. The sensor using Au electrode showed the sensitivity of 25 ㎽/decade and the sensor using Pt electrode showed the sensitivity of 26 ㎽/decade for the variation of carbon dioxide gas concentration, respectively. The sensor using Au electrode showed good selectivity compared to that using Pt electrode for carbon monoxide gas and hydro carbon gases. From the above results, the CO₂ sensor with Au electrode is very useful to measuring the CO₂ concentration.

리티움 이온 고체전해질 CO₂센서

송갑득,서무교,곽종식,이덕동 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

Carbon dioxide gas sensor, which has inner heater, is fabricated using Li ionic electrolyte as raw material which is systhesized by sol-gel method. It has either Au electrode or Pt electrode as the metal electrode of sensing electrode part. Sensing characteristics for carbon dioxide gas and interference effect for carbon monoxide gas and hydro carbon gases are investigated. The sensors using Au electrode and Pt electrode show sensitivity about 25 mV/decade and 26 mV/decade for the variation of carbon dioxide gas concentration, respectively. The sensor using Au electrode shows more exellent selectivity compared to that using Pt electrode for carbon monoxide gas and hydro carbon gases.

CaO를 첨가한 Na고체전해질 센서의 CO_2가스 감도향상에 관한 연구

곽종식,서무교,최순돈,이덕동 한국센서학회 2002 센서학회지 Vol.11 No.4

CO_2 가스 감도를 높임과 동시에 감지거동을 안정화시키기 위하여 여러 함량의 CaO가 함유된 NASICON 전해질을 낮은 온도에서 소결하여 NASICON 센서를 제작하였다. 제조된 소자는 비교적 낮은 동작온도인 250℃ 정도에서도 양호한 감도와 안정된 출력특성을 나타내었다. NASICON sensors that the NASICON electrolytes with various CaO amounts were sintered at low temperatur(900℃), were fabricated to improve CO_2 sensitivity and stability in sensing behaviors. The manufactured device was shown good sensing characteristics and stability of output electromotive force at 250℃, comparatively low operating temperature.

Sc₂O₃를 첨가한 SnO₂/Ca,Pt 가스센서의 부탄감응 특성

이윤수,성정훈,강봉휘,서무교,이덕동 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

A coprecipitation method was used for preparing Ca and Pt doped SnO_(2) powder. Components were investigated by XRD and SEM. Sc_(2)O_(3) added SnO_(2) /Ca,Pt thick film devices were fabricated by screen printing technique for butane gas detecting. By addition of Sc_(2)O_(3), the selectivity of SnO_(2) /Ca,Pt thick film for butane gas was enhanced. The sensitivity of Sc_(2)O_(3) added SnO_(2) /Ca,Pt device to 3,000 ppm butane in air was about 90% at the operating temperature. of 200℃. And the device showed good selectivity for butane gas.

리튬 이온 전도체를 이용한 히터가 내장된 CO₂센서

채유석,송갑득,강봉휘,서무교,이덕동 경북대학교 센서기술연구소 1997 센서技術學術大會論文集 Vol.8 No.1

The simple solid electrolyte carbon dioxide sensor was fabricated using Li ionic conductor with a heater and Li_(2)CO_(3)+Na_(2)CO_(3)+K_(2)CO_(3) (47.6 : 25.4 : 27.0) as a metal carbonate auxiliary phase. The electromotive force(EMF) was in excellent agreement with the EMF value calculated from the Nernst' s equation for CO_(2) gas concentration from 950 to 9,950ppm at 420℃, with the response time of 15~25 sec.. Water vapor hardly affected the sensor characteristics for relative humidity from 40% to 90%, in contrast to the case of the Li_(2)CO_(3) and Na_(2)CO_(3) + BaCO_(3)(1 : 1.7). The CO_(2) sensitivity of this sensor was stable for the test period of 240 hours.

단일전극을 가진 마이크로 가스센서의 제작 및 특성

송갑득,박영일,이상문,이윤수,최낙진,주병수,서무교,허증수,이덕동 한국센서학회 2002 센서학회지 Vol.11 No.6

센서의 안정도와 감도를 개선시킬 수 있는 단일전극을 가진 열선형 마이크로 가스센서를 제작하였다. 일반적으로, 금속산화물 반도체를 이용한 가스센서는 히터전극과 감지전극의 두 개의 전극을 가지고 있다. 제작된 센서는 히터전극위에 감지물질을 형성하여 단일 전극을 가지는 구조를 가지고 있다. 히터와 감지전극으로 사용되는 Pt는 glass 기판위에 스퍼터링법으로 형성하였으며, SnO_2 감지물질은 제작된 Pt 전극위에 열증착시켜 형성하였다. SnO_2막은 lift-off 공정을 이용해서 패턴을 형성하고 1시간 동안 산소분위기에서 열산화하였다. 제작된 소자의 크기는 1.92x.1 mm^2 이다. CO 가스에 대한 감지특성을 조사한 결과 1,000 ppm에 대해 100 mV의 출력변화를 나타내었으며, 넓은 농도범위(0 ~ 10,000 ppm에서 선형적인 전압출력을 나타내었다. 또한 가스 반응 전과 반응 후의 전압출력을 비교해 볼 때, 1 % 이내의 편차를 나타내는 우수한 회복성을 나타내었다. Micro gas sensor with single electrode was proposed for improving stability and sensitivity, Generally, metal oxide gas sensors have two electrodes for heating and sensing. This fabricated new type sensor have only a single electrode by forming a sensing material onto heating electrode. Pt as a heating and sensing electrode was sputtered on glass and a SnO_2 sensing material was thermally evaporated on Pt electrode. SnO_2 was patterned by lift-off process and then thermally oxidized in O_2 condition for 1 hr., 600 ℃. The size fabricated sensor was 1.9 x 2.1 mm^2. As a result of CO gas sensing characteristics, this sensor showed 100 mV change for 1,000 ppm and linearlity for wide range(0 ~ 10,000 ppm) of gas concentrations. And the sensor shows a good recovery characteristics of 1 % deviation compared to initial resistance.