JP5048213B2 - Semiconductor gas detector - Google Patents
Semiconductor gas detector Download PDFInfo
- Publication number
- JP5048213B2 JP5048213B2 JP2004354249A JP2004354249A JP5048213B2 JP 5048213 B2 JP5048213 B2 JP 5048213B2 JP 2004354249 A JP2004354249 A JP 2004354249A JP 2004354249 A JP2004354249 A JP 2004354249A JP 5048213 B2 JP5048213 B2 JP 5048213B2
- Authority
- JP
- Japan
- Prior art keywords
- gas
- semiconductor
- detection element
- carbon nanotubes
- insulating substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Description
絶縁基板上に設けた検出電極と感応層とを備える半導体式ガス検知素子に関する。 The present invention relates to a semiconductor gas detection element including a detection electrode and a sensitive layer provided on an insulating substrate.
従来、半導体式ガス検知素子として、例えば基板型半導体式ガス検知素子が知られている。基板型半導体式ガス検知素子は、絶縁基板上に一対の検出電極を蒸着し、その電極と接触するようにガス感応層を形成してある。そして、このガス感応層は、被検知ガスと反応することでその抵抗値が変化するものであり、この抵抗値の変化を測定することによって、被検知ガスを検知することができる。
尚、本発明における従来技術となる半導体式ガス検知素子は、一般的な技術であるため、特許文献等の従来技術文献は示さない。
Conventionally, for example, a substrate type semiconductor gas detection element is known as a semiconductor type gas detection element. In the substrate type semiconductor gas detection element, a pair of detection electrodes is vapor-deposited on an insulating substrate, and a gas sensitive layer is formed so as to be in contact with the electrodes. The gas-sensitive layer changes its resistance value by reacting with the gas to be detected, and the gas to be detected can be detected by measuring the change in the resistance value.
In addition, since the semiconductor type gas detection element used as the prior art in this invention is a general technique, prior art documents, such as a patent document, are not shown.
一方、近年、カーボンナノチューブ（ＣＮＴ）が発見され、超微細中空構造及び特異な電子特性を有していることから、次世代の高機能デバイスの基幹材料として期待されている。そして、それらの特徴を利用した様々な研究が盛んに行われており、例えば、多層のＣＮＴを、導電性を有することを利用してガスを検知するセンサに適用することが提案されている（例えば、特許文献１参照）。 On the other hand, in recent years, carbon nanotubes (CNT) have been discovered and have an ultrafine hollow structure and unique electronic properties, and thus are expected as a core material for next-generation high-performance devices. Various researches using these features have been actively conducted, and for example, it has been proposed to apply multi-layered CNTs to sensors that detect gas by using conductivity ( For example, see Patent Document 1).
しかし、前記従来の多層のＣＮＴを用いたガスセンサは、メタンや二酸化窒素等のガスを検知することができるものの、検出感度は低く、検出できるガス濃度は１００ｐｐｍ程度までであった。 However, although the conventional gas sensor using multi-layered CNT can detect gases such as methane and nitrogen dioxide, the detection sensitivity is low and the detectable gas concentration is up to about 100 ppm.
一方、ＮＯＸやハロゲンガス等の環境汚染物質に対しては、人体に重大な影響を及ぼす虞もあるため、低濃度のものであっても可能な限り検知したいとの要望があり、ｐｐｂレベルのガスまで検知できるものが求められていた。 On the other hand, for NO X and environmental pollutants such as a halogen gas, since some significant impact risk to the human body, there is a demand for the to be detected as possible be of low concentration, ppb level There was a need for a gas that could detect up to the gas.
本発明は、上記課題に鑑みてなされたものであり、ｐｐｂレベルの低濃度のガスであっても検知することができる検出感度の高い半導体式ガス検知素子を提供することを目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a semiconductor-type gas detection element having high detection sensitivity that can detect even a low-concentration gas at a ppb level.
上記目的を達成するための本発明に係る半導体式ガス検知素子の第１特徴構成は、絶縁基板上に設けた検出電極と、当該検出電極に接触するカーボンナノチューブを主成分とし、当該カーボンナノチューブを前記絶縁基板に対して垂直方向に配した感応層とを備える点にある。 The first characterizing feature of the semiconductor type gas sensing element according to the present invention for achieving the above object, a detection electrode disposed on an insulating substrate, a main component of carbon nanotubes in contact with the detection electrode, the carbon nanotubes in that it comprises a sensitive layer arranged in a direction perpendicular to the front Symbol insulating substrate.
つまり、この構成によれば、感応層としてカーボンナノチューブを用いることにより、一旦、カーボンナノチューブに吸着した被検知ガスは、常温下では脱着することがなく蓄積させることができる。このため、ｐｐｂレベルの低濃度の被検知ガスであっても、検知時間を制御することにより検知することができる。 That is, according to this configuration, by using carbon nanotubes as the sensitive layer, the gas to be detected once adsorbed on the carbon nanotubes can be accumulated without desorption at room temperature. For this reason, even a low concentration gas to be detected at the ppb level can be detected by controlling the detection time.
本発明に係る半導体式ガス検知素子の第２特徴構成は、半導体的性質を備えた前記カーボンナノチューブを用いる点にある。 The second characteristic configuration of the semiconductor gas detection element according to the present invention is that the carbon nanotube having semiconductor properties is used.
つまり、この構成によれば半導体的性質を備えたカーボンナノチューブを感応層に適用することにより、より検出感度を高めることができる。 That is, according to this configuration, the detection sensitivity can be further improved by applying the carbon nanotube having semiconducting properties to the sensitive layer.
本発明に係る半導体式ガス検知素子の第３特徴構成は、前記カーボンナノチューブの密度が、０．０１〜０．５ｇ／ｃｍ3である点にある。 A third characteristic configuration of the semiconductor gas detection element according to the present invention is that the density of the carbon nanotubes is 0.01 to 0.5 g / cm 3 .
つまり、この構成によれば、感応層のカーボンナノチューブの密度を０．０１〜０．５ｇ／ｃｍ３にすることにより、被検知ガスがカーボンナノチューブ層の内部にまで進入し易くなる。このため、被検知ガスに対する応答速度が速くなると共に、感応層の電気抵抗値が高くなり、検出感度を高くすることができる。 That is, according to this configuration, the density of the carbon nanotubes in the sensitive layer is set to 0.01 to 0.5 g / cm 3 , so that the gas to be detected can easily enter the carbon nanotube layer. For this reason, while the response speed with respect to to-be-detected gas becomes quick, the electrical resistance value of a sensitive layer becomes high, and it can make detection sensitivity high.
本発明に係る半導体式ガス検知素子の第４特徴構成は、前記基板を、アルミナを主成分とする点にある。 A fourth characteristic configuration of the semiconductor gas detection element according to the present invention is that the substrate is mainly composed of alumina.
つまり、この構成によれば、アルミナを主成分とする基板の表面は完全な平滑ではなくナノオーダーの凹凸を有するため、アンカー効果により検出電極との接合強度を高めることができる。このため、電気伝導度の測定においてロスが少なくなるため、被検知ガスが吸着した際の抵抗の変化が小さい場合も検知することが可能となり、被検知ガスの検出感度を高くすることができる。 In other words, according to this configuration, the surface of the substrate mainly composed of alumina is not completely smooth but has nano-order irregularities, so that the bonding strength with the detection electrode can be increased by the anchor effect. For this reason, since the loss in the measurement of electric conductivity is reduced, it is possible to detect even when the change in resistance when the gas to be detected is adsorbed is small, and the detection sensitivity of the gas to be detected can be increased.
本発明に係る半導体式ガス検知素子は、絶縁基板上に設けた検出電極と、当該検出電極に接触するカーボンナノチューブを主成分とする感応層とを備えるものである。これにより、ｐｐｂレベルの低濃度のガスであっても検知可能なガス検知素子を提供することができる。 The semiconductor type gas detection element according to the present invention includes a detection electrode provided on an insulating substrate and a sensitive layer mainly composed of carbon nanotubes in contact with the detection electrode. Thereby, it is possible to provide a gas detection element capable of detecting even a low concentration gas at a ppb level.
以下、本発明に係る半導体式ガス検知素子の一実施形態について、図面を参照して説明する。ここでは、絶縁基板上に一対の検出電極を設けると共に、これら一対の検出電極に亘ってガス感応層を設けた基板型半導体式ガス検知素子を例示するが、これに限られるものではない。その他の半導体式ガス検知素子としては、熱線型半導体式ガス検知素子、直熱型半導体式ガス検知素子、傍熱型半導体式ガス検知素子等が挙げられる。 Hereinafter, an embodiment of a semiconductor gas detection element according to the present invention will be described with reference to the drawings. Here, a substrate-type semiconductor gas detection element in which a pair of detection electrodes is provided on an insulating substrate and a gas sensitive layer is provided across the pair of detection electrodes is illustrated, but the present invention is not limited thereto. Examples of other semiconductor gas detection elements include a hot-wire semiconductor gas detection element, a direct heat semiconductor gas detection element, and an indirectly heated semiconductor gas detection element.
本実施形態に係る半導体式ガス検知素子は、図１に示すように、絶縁基板１の表面に一対の櫛型の検出電極２、３が蒸着して設けてあり、これら電極と接触するようにカーボンナノチューブを主成分とする感応層４が設けてある。絶縁基板１の裏面には、基板型半導体式ガス検知素子の動作温度を維持するため、薄膜ヒータ５が設けてある。 As shown in FIG. 1, the semiconductor gas detection element according to the present embodiment has a pair of comb-shaped detection electrodes 2 and 3 deposited on the surface of an insulating substrate 1 so as to be in contact with these electrodes. A sensitive layer 4 composed mainly of carbon nanotubes is provided. A thin film heater 5 is provided on the back surface of the insulating substrate 1 in order to maintain the operating temperature of the substrate type semiconductor gas detection element.
絶縁基板１は、従来の基板型半導体式ガス検知素子に用いられるものが好ましく適用でき、その大きさ、形状等は特に限定されない。また、絶縁基板１の材質は、絶縁体であればよく、例えば、アルミナ、シリカ、ガラス等が適用できる。中でもアルミナを絶縁基板１として用いることは、その表面は完全な平滑ではなく、ナノオーダーの凹凸を有するため、アンカー効果により検出電極２、３や薄膜ヒータ５との接合を強固にすることができるため好ましい。 The insulating substrate 1 can be preferably applied to those used in conventional substrate type semiconductor gas sensing elements, and the size, shape, etc. are not particularly limited. Moreover, the material of the insulating substrate 1 should just be an insulator, for example, an alumina, a silica, glass etc. are applicable. Among them, the use of alumina as the insulating substrate 1 has a surface that is not completely smooth and has nano-order irregularities, so that the bonding with the detection electrodes 2 and 3 and the thin film heater 5 can be strengthened by the anchor effect. Therefore, it is preferable.
また、検出電極２、３及び薄膜ヒータ５についても、特に制限されるものではなく、例えば、白金、金、白金パラジウム合金等、従来の基板型半導体式ガス検知素子と同様のものを用いることができる。特に白金は非常に耐久性に優れた材料であり、検出電極２、３や薄膜ヒータ５に好ましく適用することができる。 Further, the detection electrodes 2 and 3 and the thin film heater 5 are not particularly limited. For example, the same electrodes as those of a conventional substrate type semiconductor gas detection element such as platinum, gold, platinum palladium alloy, etc. may be used. it can. In particular, platinum is a material having extremely excellent durability and can be preferably applied to the detection electrodes 2 and 3 and the thin film heater 5.
感応層４は、検出電極２及び３と接触するように設けてあり、所謂カーボンナノチューブを主成分とするものであれば特に限定することなく適用することができる。これにより、ＮＯＸガス及びハロゲンガスを選択的に検知することができる。また、カーボンナノチューブの形状も特に制限はない。例えば、図２に示すように既知のアーク放電法やレーザー蒸発法によって得られる繊維状のカーボンナノチューブを絶縁基板１上に網目状に配したものや、図３に示すように絶縁基板１に対して、長さ５〜１００μｍ程度のカーボンナノチューブを垂直方向に配向させたもの等、様々な形状のものを適用することができる。 The sensitive layer 4 is provided so as to be in contact with the detection electrodes 2 and 3 and can be applied without particular limitation as long as it has so-called carbon nanotubes as a main component. Thereby, NO X gas and halogen gas can be selectively detected. Further, the shape of the carbon nanotube is not particularly limited. For example, as shown in FIG. 2, fibrous carbon nanotubes obtained by a known arc discharge method or laser evaporation method are arranged in a mesh on the insulating substrate 1, or as shown in FIG. Thus, various shapes such as those in which carbon nanotubes having a length of about 5 to 100 μm are oriented in the vertical direction can be applied.
特に絶縁基板１に対して垂直方向に配向させたカーボンナノチューブは、絶縁基板１上に触媒金属を付着させた後、加熱して熱化学気相成長法によって製造することができる。このため、絶縁基板１上において、触媒金属の配置を制御することによって感応層４の形状を任意に定めることができる。また、カーボンナノチューブの垂直方向の長さを制御することも可能であるため、長くすることにより被検知ガスに対する反応領域を広げることができる。さらに、検出電極２、３として白金を用いれば、図３に示すように白金上においてはカーボンナノチューブの成長を抑えることができる。このため、従来の検出電極を覆う感応層を有するガス検知素子に比べて、ガス検知に関与する感応層の表面積を増加させることができ、被検知ガスの検出感度を高めることができる。 In particular, carbon nanotubes oriented in a direction perpendicular to the insulating substrate 1 can be manufactured by thermal chemical vapor deposition after heating a catalyst metal on the insulating substrate 1 and then heating. For this reason, the shape of the sensitive layer 4 can be arbitrarily determined by controlling the arrangement of the catalytic metal on the insulating substrate 1. In addition, since the length of the carbon nanotube in the vertical direction can be controlled, the reaction region for the gas to be detected can be widened by increasing the length. Further, if platinum is used as the detection electrodes 2 and 3, the growth of carbon nanotubes can be suppressed on the platinum as shown in FIG. For this reason, compared with the conventional gas detection element which has a sensitive layer which covers a detection electrode, the surface area of the sensitive layer which concerns in gas detection can be increased, and the detection sensitivity of to-be-detected gas can be raised.
カーボンナノチューブは、単層のカーボンナノチューブでも中空構造が幾重にも重なった多層のカーボンナノチューブでも適用可能であるが、特には単層のカーボンナノチューブであって、半導体的性質を有するものであることが好ましい。尚、半導体的性質を有するカーボンナノチューブは、電極間に１．７Ｖ以上の電圧を印加して、金属的（電気抵抗が低い）性質を持つ単層及び多層カーボンナノチューブに過剰の電流を流して焼ききる方法、すなわち電気的ブレイクダウンを行うことにより選択的に製造することができる。 The carbon nanotubes can be applied to single-walled carbon nanotubes or multi-walled carbon nanotubes with multiple hollow structures, but in particular, single-walled carbon nanotubes that have semiconducting properties. preferable. Carbon nanotubes having semiconducting properties are baked by applying a voltage of 1.7 V or more between the electrodes and passing an excess current through single-walled and multi-walled carbon nanotubes having metallic (low electrical resistance) properties. Can be selectively manufactured by performing an electrical breakdown, that is, an electrical breakdown.
また、感応層４におけるカーボンナノチューブの密度は製造時の温度を制御することによって任意に制御可能であるが、後述する実施例において示すように０．０１〜０．５ｇ／ｃｍ３であることが好ましい。すなわち、密度が小さくなることにより被検知ガスが感応層４の内部にまで拡散し易くなる。このため、応答速度が速やかになると共に、感応層４の電気抵抗値が高くなり、検出感度を高くすることができる。一方、密度が小さくなりすぎると吸着サイトも減少するため、検出感度が低下する。 Further, the density of the carbon nanotubes in the sensitive layer 4 can be arbitrarily controlled by controlling the temperature at the time of production, but it is 0.01 to 0.5 g / cm 3 as shown in Examples described later. preferable. That is, the gas to be detected is easily diffused to the inside of the sensitive layer 4 by decreasing the density. For this reason, the response speed becomes rapid, the electric resistance value of the sensitive layer 4 becomes high, and the detection sensitivity can be increased. On the other hand, if the density is too small, the adsorption sites are also reduced, so that the detection sensitivity is lowered.
このような半導体式ガス検知素子は、感応層４を構成するカーボンナノチューブに一旦吸着した被検知ガスが常温においては、脱着することなく蓄積させることができる。このため、ｐｐｂレベルの濃度の被検知ガスであっても検知時間を長くすることにより検出することができる。そして、薄膜ヒータ５をオンにして感応層４を加熱することにより、吸着している被検知ガスを脱着させることができるため、繰り返しガス検知が可能となる。 In such a semiconductor gas detection element, the detected gas once adsorbed on the carbon nanotubes constituting the sensitive layer 4 can be accumulated without desorption at room temperature. For this reason, even a gas to be detected having a concentration of ppb level can be detected by extending the detection time. Since the gas to be detected can be desorbed by turning on the thin film heater 5 and heating the sensitive layer 4, it is possible to repeatedly detect the gas.
尚、その他の半導体式ガス検知素子の構成、機能については、従来公知の半導体式ガス検知素子と同様である。そして、本発明に係る半導体式ガス検知素子は、既知のガス検知回路等に組み込むことにより、ガスセンサ等に適用することができる。 In addition, about the structure and function of another semiconductor type gas detection element, it is the same as that of a conventionally well-known semiconductor type gas detection element. The semiconductor gas detection element according to the present invention can be applied to a gas sensor or the like by being incorporated in a known gas detection circuit or the like.
以下に本実施形態に係る半導体式ガス検知素子を用いて、被検知ガスに接触させた際の抵抗変化率を測定した実施例について説明する。尚、抵抗変化率とは、「空気中におけるセ電気抵抗値〔Ｒ（ａｉｒ）〕」に対する「ガスのそれぞれの濃度における電気抵抗値〔Ｒ（ｇａｓ）〕」の比を表す。 An example in which the rate of change in resistance when contacting a gas to be detected using the semiconductor gas detection element according to the present embodiment will be described below. The resistance change rate represents the ratio of “electric resistance value [R (gas)] at each concentration of gas” to “cell electric resistance value [R (air)]” in air.
絶縁基板１として、アルミナ基板を用い、従来の基板型半導体式ガス検知素子の製造方法と同様にして、白金の検出電極２、３及び白金の薄膜ヒータを蒸着させた。次いで、絶縁基板上に金属触媒である鉄触媒を配置し、アセチレンガスを原料ガスに用いた熱化学気相成長法により図３に示すように絶縁基板１に対して、垂直方向に配向したカーボンナノチューブが得られた。このときのカーボンナノチューブの長さは１２μｍであり、密度は０．０５ｇ／ｃｍ３であった。 An alumina substrate was used as the insulating substrate 1, and platinum detection electrodes 2 and 3 and a platinum thin film heater were vapor-deposited in the same manner as in the conventional method of manufacturing a substrate type semiconductor gas detection element. Next, an iron catalyst which is a metal catalyst is disposed on the insulating substrate, and carbon oriented in the vertical direction with respect to the insulating substrate 1 as shown in FIG. 3 by a thermal chemical vapor deposition method using acetylene gas as a source gas. Nanotubes were obtained. The length of the carbon nanotube at this time was 12 μm, and the density was 0.05 g / cm 3 .
このようにして得られた基板型半導体式ガス検知素子を用いて、ＮＯ２ガスに対する検出感度を調べた。すなわち、ヒータのオン／オフを切り替えながら、１８０秒間オンした後、オフにした際に１０ｐｐｂ、５０ｐｐｂ、１００ｐｐｂ、５００ｐｐｂの濃度のＮＯ２ガスを順に加え、電気抵抗値の変化を測定した。その結果、図４に示すようにｐｐｂレベルのＮＯ２ガスであっても検出可能であることが分かった。 Using the substrate type semiconductor gas sensing element thus obtained, the detection sensitivity for NO 2 gas was examined. That is, after switching on / off the heater for 180 seconds and then turning it off, NO 2 gas having concentrations of 10 ppb, 50 ppb, 100 ppb, and 500 ppb was sequentially added to measure the change in electrical resistance value. As a result, it was found that even ppb level NO 2 gas was detectable as shown in FIG.
実施例１で作製した基板型半導体式ガス検知素子を用いて、実施例１と同様にヒータのオン／オフを切り替えながら、１８０秒間オンした後、オフにした際に０．０５ｐｐｍ、０．１ｐｐｍ、０．５ｐｐｍ、１ｐｐｍの濃度のＣｌ２ガスを順に加え、電気抵抗値の変化を測定した。その結果、図５に示すように低濃度のＣｌ２ガスに対しても検出可能であることが分かった。 Using the substrate type semiconductor gas detection element produced in Example 1, the heater was turned on / off in the same manner as in Example 1 and turned on for 180 seconds and then turned off. Then, Cl 2 gas having a concentration of 0.5 ppm and 1 ppm was sequentially added, and a change in electric resistance value was measured. As a result, it was found that detection was possible even with a low concentration of Cl 2 gas as shown in FIG.
実施例１で使用した基板型半導体式ガス検知素子において、カーボンナノチューブの密度を０．００５〜０．９ｇ／ｃｍ３の範囲で変えて、１ｐｐｍの濃度のＮＯ２ガスに対する抵抗変化値を測定した。その結果、図６に示すようにカーボンナノチューブの密度が０．０１〜０．５ｇ／ｃｍ３である場合に特に検出感度が高くなることが分かった。 In the substrate type semiconductor gas sensing element used in Example 1, the density of carbon nanotubes was changed in the range of 0.005 to 0.9 g / cm 3 , and the resistance change value with respect to NO 2 gas having a concentration of 1 ppm was measured. . As a result, it was found that the detection sensitivity was particularly high when the density of the carbon nanotubes was 0.01 to 0.5 g / cm 3 as shown in FIG.
実施例１で作製した基板型半導体式ガス検知素子を用いて、カーボンナノチューブ中の電流密度を０．１〜１０００Ａ／ｃｍ２の範囲で変えて、１ｐｐｍの濃度のＮＯ２ガスに対する抵抗変化値を測定した。その結果、図７に示すように電流密度が１〜１０Ａ／ｃｍ２である時に、検出感度が高くることが分かった。すなわち、このような電流密度となるように電極間電圧を制御することによって、検出感度を高めることができる。 Using the substrate-type semiconductor gas sensing element produced in Example 1, the current density in the carbon nanotube was changed in the range of 0.1 to 1000 A / cm 2 , and the resistance change value with respect to NO 2 gas having a concentration of 1 ppm was obtained. It was measured. As a result, it was found that the detection sensitivity was high when the current density was 1 to 10 A / cm 2 as shown in FIG. That is, the detection sensitivity can be increased by controlling the interelectrode voltage so as to obtain such a current density.
本発明に係る半導体式ガス検知素子は、従来のガスセンサ、ガス警報器、ガス測定器等に適用することができる。 The semiconductor gas detection element according to the present invention can be applied to conventional gas sensors, gas alarms, gas measuring devices, and the like.
１ 絶縁基板
２、３ 検出電極
４ 感応層
５ 薄膜ヒータ
DESCRIPTION OF SYMBOLS 1 Insulating substrate 2, 3 Detection electrode 4 Sensitive layer 5 Thin film heater
Claims (4)
は２に記載の半導体式ガス検知素子。 3. The semiconductor type gas detection element according to claim 1, wherein a density of the carbon nanotube is 0.01 to 0.5 g / cm 3 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004354249A JP5048213B2 (en) | 2004-12-07 | 2004-12-07 | Semiconductor gas detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004354249A JP5048213B2 (en) | 2004-12-07 | 2004-12-07 | Semiconductor gas detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2006162431A JP2006162431A (en) | 2006-06-22 |
| JP5048213B2 true JP5048213B2 (en) | 2012-10-17 |
Family
ID=36664622
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2004354249A Expired - Fee Related JP5048213B2 (en) | 2004-12-07 | 2004-12-07 | Semiconductor gas detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5048213B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5155767B2 (en) * | 2008-08-04 | 2013-03-06 | 国立大学法人大阪大学 | Gas detection element |
| US9562884B2 (en) | 2013-06-05 | 2017-02-07 | Institute of Microelectronics, Chinese Academy of Sciences | Method for manufacturing NO2 gas sensor for detection at room temperature |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ATE402407T1 (en) * | 1999-12-15 | 2008-08-15 | Univ Leland Stanford Junior | CARBON NANOTUBE DEVICE |
| JP2003227806A (en) * | 2002-02-01 | 2003-08-15 | Kansai Research Institute | Gaseous substance-detecting method |
| JP3924472B2 (en) * | 2002-02-05 | 2007-06-06 | 株式会社ジェイテクト | Sensors using carbon nanotubes |
| JP2004059409A (en) * | 2002-07-31 | 2004-02-26 | Junji Nakamura | Carbon nano material, its manufacturing method and hydrogen storage material |
| AU2003291133A1 (en) * | 2002-11-26 | 2004-06-18 | Carbon Nanotechnologies, Inc. | Carbon nanotube particulates, compositions and use thereof |
| JP2004325142A (en) * | 2003-04-22 | 2004-11-18 | Matsushita Electric Works Ltd | Gas sensor |
-
2004
- 2004-12-07 JP JP2004354249A patent/JP5048213B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2006162431A (en) | 2006-06-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wei et al. | A novel SnO2 gas sensor doped with carbon nanotubes operating at room temperature | |
| US8683672B2 (en) | Nanomaterial-based gas sensors | |
| KR101027074B1 (en) | nanostructure gas sensors and nanostructure gas sensor array with metal oxide layer and method of producing the same | |
| EP2745102B1 (en) | Chemical sensor based on highly organized single walled carbon nanotube networks | |
| US20050169798A1 (en) | Sensitivity control for nanotube sensors | |
| Inaba et al. | Effect of mixing ratio on NO2 gas sensor response with SnO2-decorated carbon nanotube channels fabricated by one-step dielectrophoretic assembly | |
| JP4320316B2 (en) | Sensor for detecting chemical substances | |
| JP5255066B2 (en) | Gas sensor with improved selectivity | |
| US20120212242A1 (en) | Graphene-Based Sensor | |
| US8720251B2 (en) | Gas sensing system | |
| JP4208839B2 (en) | Nanotube sensor | |
| KR101358245B1 (en) | Hydrogen sensor and method for manufacturing the same | |
| US9418857B2 (en) | Sensor component for a gas and/or liquid sensor, production method for a sensor component for a gas and/or liquid sensor, and method for detecting at least one material in a gaseous and/or liquid medium | |
| JP5155767B2 (en) | Gas detection element | |
| Lee et al. | Realization of nanolene: a planar array of perfectly aligned, air‐suspended nanowires | |
| Lee et al. | Direct integration of carbon nanotubes on a suspended Pt microheater for hydrogen gas sensing | |
| JP5048213B2 (en) | Semiconductor gas detector | |
| WO2018147101A1 (en) | Gas sensor element, gas detection device and gas detection method | |
| JP6035087B2 (en) | Gas sensor, gas measuring device, and gas sensor manufacturing method | |
| JP4870938B2 (en) | Manufacturing method of semiconductor gas detection element | |
| KR101331021B1 (en) | Biosensor | |
| Lu et al. | Fabrication of carbon-nanotube-based sensor array and interference study | |
| JP5246868B2 (en) | Volatile organic substance detection sensor | |
| KR102315828B1 (en) | A nano chemical sensor for detecting electrostatic capacity change using nano materials having metal or semiconductor property as an active material | |
| KR100771526B1 (en) | Gas sensor and manufactutring method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20071126 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20091014 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20100826 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20101025 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110414 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110613 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20111201 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120228 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20120228 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20120404 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120705 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120719 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150727 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5048213 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |