TW202024604A - Gas-sensing apparatus - Google Patents

Abstract

A gas-sensing apparatus includes a gas-sensing device and a light-emitting member spaced apart from the gas-sensing device. The gas-sensing device includes a light and gas sensing member that reacts with a measurable gas and has an organic semiconductor material, a first electrode that is connected to the light and gas sensing member, and a second electrode that is spaced apart from the first electrode and is connected to the light and gas sensing member. After the light and gas sensing member reacts with the measurable gas, the light-emitting member is for emitting light toward and absorbed by the light and gas sensing member.

Description

Gas sensing equipment

The present invention relates to a sensing device, in particular to a gas sensing device.

In the past, the gas sensing film formed of inorganic semiconductor materials in the gas sensor used nitrogen, air, heating (such as infrared light) and other methods after sensing the gas to restore the current value generated after sensing to the value before sensing The current value for the next sensing. However, this method has (1) the recovery time is too long; (2) when the recovery time is insufficient, the current signal generated after the next sensing will be reduced and not obvious or the current signal will vary with use The number of times increases and increases, so that the repeatability is poor or can no longer be used.

Nano letters , 2003, vol.3, NO.7, 929-933 reveals a gas sensor that can sense gases or organic volatiles at room temperature, and uses carbon nanotubes as the sensing film. The gas sensor can use UV light to promote gas desorption, so that the current value generated after sensing is restored to the current value before sensing, thereby achieving the characteristic of reducing the recovery time.

An academic paper on "Single Zinc Oxide Nanowire Nitric Oxide Gas Sensor Fabrication and Adsorption Kinetics Research, Zheng Yihua, National Tsinghua University" reveals a gas sensor that can sense gas at room temperature, and Zinc oxide nanowire is used as the sensing film. The gas sensor can use a fluorescent lamp to irradiate the sensing film, so that the current value generated after the sensing is restored to the current value before the sensing, and compared with UV light, it is convenient and quick to recover.

US Patent Publication No. 5448906 discloses a gas sensor capable of sensing gas at room temperature. The gas sensor includes a polycrystalline semiconductor oxide film for the gas to be measured, two electrodes connected to the polycrystalline semiconductor oxide film and located on the upper and left sides of the polycrystalline semiconductor oxide film, and one A UV lamp above the polycrystalline semiconductor oxide film. The light source provided by the UV lamp can be absorbed by the polycrystalline semiconductor oxide film, so that the adsorbed gas to be measured can be photodesorption on the polycrystalline semiconductor oxide film.

Although the above-mentioned gas sensor can release the gas to be measured from the inorganic semiconductor film through the fluorescent lamp and UV lamp, so that the current value generated after the sensing can be restored to the current value before the sensing, the recovery time is still too long. During the recovery process, the current value changes slowly.

Therefore, the object of the present invention is to provide a gas sensing device with a short current recovery time.

Therefore, the gas sensing device of the present invention includes a gas sensing device and a light-emitting element that is spaced apart from the gas sensing device. The gas sensing device includes a light and gas sensing element that is used to interact with the gas to be measured and includes an organic semiconductor material, a first electrode connected to the light and gas sensing element, and a spaced apart from the first electrode And connected to the second electrode of the light and gas sensor. The light-emitting element is used to provide light that is irradiated toward the light and gas sensing element and can be absorbed by the light and gas sensing element.

The effect of the present invention is that through the combination of the light-emitting element and the light and gas sensing element, the light-emitting element is turned on after sensing. During the recovery process, the light and gas sensing element can absorb light and can The light signal writes the current signal, and at the same time, the light can also promote the desorption of the gas to be measured, so that the current value generated after the sensing can quickly rise and return to the current value before the sensing, and then the recovery efficiency is improved for the next step. One-time sensing. Therefore, the gas sensing device of the present invention has a short current recovery time.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers.

1 and 2, a first embodiment of the gas sensing device of the present invention is installed in a transparent glass container 3 filled with nitrogen or air, and includes a sensing device 1 and a light emitting element 2. The glass container 3 has a volume of 30 mm ³ and includes an air inlet 31 for the gas to be measured to enter, and an air outlet 32 opposite to the air inlet 31. The gas to be measured is, for example, but not limited to, oxidizing gas or reducing gas. The gas to be measured is, for example, but not limited to, ammonia, acetone, nitrogen monoxide, or nitrogen dioxide.

The gas sensing device 1 includes a first electrode layer 11, a second electrode layer 12 spaced apart from the first electrode layer 11, and a second electrode layer 12 located between the first electrode layer 11 and the second electrode layer 12 and connected The light and gas sensors 13 of the first electrode layer 11 and the second electrode layer 12.

The first electrode layer 11 has two opposite surfaces 111 and has a plurality of through holes 10 penetrating the surfaces 111 and used to expose the light and gas sensor 13. The material of the first electrode layer 11 is, for example, but not limited to, metal, metal compound, or conductive organic material. The metal is, for example, but not limited to, aluminum, gold, silver, calcium, nickel, or chromium. The metal compound is, for example, but not limited to, zinc oxide, molybdenum oxide, or lithium fluoride. The conductive organic material is, for example, but not limited to, polydioxyethylthiophene-polystyrene sulfonic acid. The thickness of the first electrode layer 11 ranges from 0.01 μm to 1 μm. The size of the through holes 10 ranges from 10 nm to 1000 nm. In the first embodiment, the material of the first electrode layer 11 is aluminum, and the thickness is 60 nm, and the size of the through holes 10 is 200 nm.

The material of the second electrode layer 12 is, for example, but not limited to, indium tin oxide, metal, metal compound, or conductive organic material. The metal is, for example, but not limited to, aluminum, gold, silver, calcium, nickel, or chromium. The metal compound is, for example, but not limited to, zinc oxide, molybdenum oxide, or lithium fluoride. The conductive organic material is, for example, but not limited to, polydioxyethylthiophene-polystyrene sulfonic acid [PEDOT:PSS]. The thickness of the second electrode layer 12 ranges from 2 nm to 1000 nm. In the first embodiment, the material of the second electrode layer 12 is indium tin oxide, and the thickness is 200 nm.

The light and gas sensor 13 is located on one surface 111 of the first electrode layer 11. The light and gas sensor 13 is used to interact with the gas to be measured and includes organic semiconductor materials. The organic semiconductor material such as but not limited to poly(9,9-dioctylfluorene) [poly(9,9-dioctylfluorene), referred to as PFO], 9,9-dioctylfluorene-benzothiadiazole copolymer [ poly(9,9-dioctylfluorene-co-benzothiadiazole), referred to as F8BT], 9,9-dioctylfluorene-N-(4-butylphenyl) diphenylamine copolymer {poly[9,9-dioctylfluorene-co -N-(4-butylphenyl)diphenylamine], referred to as TFB}, poly(3-hexylthiophene) [poly(3-hexylthiophene), referred to as P3HT], poly{4,8-bis(5-(2-乙) Hexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-4-(2-ethylhexyloxycarbonyl)-3- Fluoro-thieno[3,4-b]thiophen-2,6-diyl)} {poly[4,8-bis(5-(2-ethylhexyl)thiophene-2-yl)-benzo[1,2 -b;4,5-b']dithiophene-2,6-diyl-4-(2-ethylhexyloxycarbonyl)-3-fluoro-thieno[3,4-b]-thiophene))-2,6-diyl], Abbreviated as PBDTTT-EFT}, poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b;4,5-b']dithiophene-2,6-diyl} {3-Fluoro-2-[(2-ethylhexyl)carbonyl]-thieno[3,4-b]thiophenediyl)} {poly[4,8-bis[(2-ethylhexyl)oxy]benzo [1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]-thiophenediyl], abbreviated PTB7}, or, poly{4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6 -Diyl-4-(2-ethylhexyl)-thieno[3,4-b]thiophen-2,6-diyl}{poly[4,8-bis(5-(2-ethylhexyl) thiophene-2-yl)-benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-4-(2-ethylhexanoyl)-thieno[3,4-b]-thiophene)- 2,6-diyl], referred to as PBDTTT-CT} Wait. The 9,9-dioctylfluorene-benzothiadiazole copolymer such as but not limited to 9,9-dioctylfluorene-2,1,3-benzothiadiazole copolymer, or 9,9-diazole Octylfluorene-1,2,3-benzothiadiazole copolymer, etc. The thickness of the light and gas sensor 13 ranges from 10 nm to 300 nm. In the first embodiment, the thickness of the light and gas sensor 13 is 20 nm.

The light emitting element 2 is located above the first electrode layer 11 of the gas sensing device 1, and after the light and gas sensing element 13 interacts with the gas to be measured, it is used to provide a direction toward the light and gas sensing element 13 irradiates and passes through the through holes 10 of the first electrode layer 11 to contact the light and gas sensor 13. The light-emitting element 2 is, for example, a visible light lamp, an ultraviolet light lamp, or an infrared light lamp.

1 and 3, a second embodiment of the gas sensing device of the present invention is installed in the glass container 3 as described in the first embodiment, and includes a gas sensing device 1 and a light emitting element 2.

The gas sensing device 1 includes a first electrode layer 11, a second electrode layer 12 spaced apart from the first electrode layer 11, a light and gas sensor 13, and a dielectric layer 14.

The first electrode layer 11 is the same as the first electrode layer 11 of the first embodiment, so it will not be repeated here. The second electrode layer 12 is spaced apart from the first electrode layer 11. The second electrode layer 12 is the same as the second electrode layer 12 of the first embodiment, so it will not be repeated here.

The dielectric layer 14 is located between one surface 111 of the first electrode layer 11 and the second electrode layer 12 and connects one of the surfaces 111 of the first electrode layer 11 and the second electrode layer 12. The material of the dielectric layer 14 is, for example, but not limited to, poly(vinylphenol) (PVP), polymethylmethacrylate (PMMA), or poly(vinyl alcohol) (PVA). )Wait. The thickness of the dielectric layer 14 ranges from 200 nm to 400 nm. The dielectric layer 14 has a plurality of through holes 20 respectively communicating with the through holes 10 of the first electrode layer 11. The size of the through holes 20 of the dielectric layer 14 ranges from 100 nm to 300 nm.

The light and gas sensor 13 is arranged opposite to the dielectric layer 14, and is connected to the other surface 111 of the first electrode layer 11, and extends into the through holes 10 of the first electrode layer 11 and the dielectric layer. The through holes 20 of the layer 14 are connected to the second electrode layer 12. The light and gas sensor 13 is the same as the light and gas sensor 13 of the first embodiment, so it will not be repeated here.

The light-emitting element 2 is located above the light and gas sensing element 13 of the gas sensing device 1, and after the light and gas sensing element 13 interacts with the gas to be measured, it is used to provide a direction toward the light and gas sensing element. The light irradiated by the test piece 13. The light-emitting element 2 is the same as the light-emitting element 2 of the first embodiment, so it will not be repeated.

When operating the gas sensing device of the first embodiment and the second embodiment, the first electrode layer 11 and the second electrode layer 12 of the gas sensing device 1 are connected to an electrical device (not shown), The electrical equipment includes a voltage supply (not shown) and a current detector (not shown) to provide voltage through the voltage supply and output current through the current detector. The voltage of the voltage supply is adjusted according to the light and gas sensor 13 selected in the gas sensor device 1. Then, the gas to be measured is introduced into the glass container 3, and the gas to be measured is brought into contact with the light and the gas sensing element 13 of the gas sensing device 1 of the gas sensing device during a sensing period, where At the same time, the current detector will continuously output the sensed current value during this sensing period. Then, stop the gas to be measured from contacting the light and gas sensing element 13 and turn on the light emitting element 2. The light emitting element 2 emits light irradiated toward the light and gas sensing element 13, and the light contacts the light and gas sensing element 13 during a recovery period, and during this recovery period, the current detector Will continuously output the return current value.

Referring to Table 1, in the present invention, experimental data of gas sensing devices numbered 1 to 7 are provided. The gas sensing devices numbered 1 to 5 are the gas sensing devices of the first embodiment, and the numbers 1 to 5 differ in the material of the sensing element 13 of the gas sensing device 1 and the light emitted by the light emitting element 2 , See Table 1. The gas sensing devices numbered 6 to 7 are the gas sensing devices of the first embodiment, and the difference from the numbers 1 to 5 is that the non-luminous element 2 is used for recovery by passing in air. The gas to be measured is ammonia, and the concentration is 300 ppb.

Table 1 Numbering Light and gas sensor 13 During sensing Light-emitting parts 2 Reply period Total time (seconds) 0 second 30 seconds Total time (seconds) 0 second 30 seconds When it ends Material Current value (μA) Current value (μA) Light Wavelength (nm) Strength (W/m ² ) Current value (μA) Current value (μA) Current value (μA) 1 PBDTTT-CT 30 0.91 0.78 Ultraviolet light 365 1 32 Is the current value at the 30th second during the induction period 2.04 0.93 2 PBDTTT-CT 30 0.91 0.77 Visible light 465 1 41 0.77 0.91 3 PBDTTT-CT 30 0.82 0.69 Infrared light 940 1 250 0.82 0.69 4 P3HT 30 2.40 2.04 Ultraviolet light 365 1 31 2.04 3.35 5 P3HT 30 2.31 1.94 Visible light 465 1 32 1.94 2.44 6 PBDTTT-CT 30 0.76 0.63 no - - 265 0.76 0.63 7 P3HT 30 1.90 1.43 no - - 305 1.90 1.90

In order to illustrate the reason why the gas sensing device of the present invention can make the current value generated after sensing rise rapidly and return to the current value before sensing, one of the main contributions comes from the ability to write optical signals into the current signals. The present invention provides a The test case of the gas sensing device can be used to obtain the desorption amount of the gas to be tested during the recovery period. The gas sensing device of this test example is installed in a transparent glass container 3 filled with nitrogen or air, and includes a gas sensing device 1 and a light emitting element 2. The glass container 3 is as described above. 4, the gas sensing device 1 includes a first electrode layer 11, a second electrode layer 12 spaced apart from the first electrode layer 11, and a second electrode layer 12 located on the first electrode layer 11 and opposite to the second electrode layer. The light and gas sensing element 13 of the layer 12, and a light and gas sensing element 13 located between the first electrode layer 11 and the second electrode layer 12 and opposite to the light and gas sensing element 13 and connecting the first electrode layer 11 and the first electrode layer 11 The piezoelectric layer 15 of the two electrode layer 12.

The first electrode layer 11 has two oppositely arranged surfaces 111. The material of the first electrode layer 11 is gold. The material of the second electrode layer 12 is gold. The light and gas sensor 13 and the piezoelectric layer 15 are respectively located on the surfaces 111 of the first electrode layer 11, and the piezoelectric layer 15 is located between the first electrode layer 11 and the second electrode layer 12. The material of the light and gas sensor 13 is the same as that of the light and gas sensor 13 of the first embodiment. The material of the piezoelectric layer 15 is quartz. The light-emitting element 2 is the same as the light-emitting element 2 numbered 2 in the first embodiment. The first electrode layer 11, the second electrode layer 12, and the piezoelectric layer 15 of the gas sensing device 1 are wafers in a crystal oscillator measurement system model QCM922A of Seiko EG&G, Japan.

When operating the gas sensing device of the test example, the first electrode layer 11 and the second electrode layer 12 of the gas sensing device 1 are connected to an electrical device (not shown), and the electrical device includes a frequency Counter (not shown). The gas to be measured is introduced into the glass container 3, and the gas to be measured is brought into contact with the light and the gas sensing element 13 of the gas sensing device 1 of the gas sensing device during a sensing period. At the same time, The frequency counter will continuously output the sensed frequency value during this sensing period. Then, stop the gas to be measured from contacting the light and gas sensing element 13 and turn on the light emitting element 2. The light-emitting element 2 emits light irradiated toward the light and gas sensing element 13, and the light contacts the light and gas sensing element 13 during a recovery period, and during this recovery period, the frequency counter Will continuously output the return frequency value. The sensing frequency value and the recovery frequency value are taken into the sauerbrey equation, and the adsorption amount and desorption amount of the gas to be measured are converted.

Refer to Figure 5, which is a data graph obtained by using the gas sensing device No. 2 under illuminated and non-illuminated conditions, with a peak bottom as the boundary, and the current change rate during the sensing period before the peak bottom. After the peak bottom is the current change rate during the recovery period, where the upper line is performed under illuminated conditions and the lower line is performed under non-illuminated conditions. The current change rate is [(AB)/A ]×100%, A represents the current value when the light and gas sensing element 13 does not interact with the gas to be measured, and B represents the current value during the sensing period or the current value during the recovery period. Refer to Figure 6, which is a graph of data obtained by using the gas sensing device of the test example under illuminated and unilluminated light, and with a peak bottom as the boundary line, before the peak bottom is the frequency difference during the sensing period. After the peak bottom is the frequency difference during the recovery period, where the upper line is performed under illuminated conditions, and the lower line is performed under non-illuminated conditions. The frequency difference is (CD), and C represents the light And the frequency value when the gas sensing element 13 does not interact with the gas to be measured, and D represents the frequency value during the sensing period or the frequency value during the recovery period. It can be seen from the upper line of Figure 6 that at the 30th second of the recovery period, the frequency value generated after sensing rebounded but did not return to the pre-sensing frequency value, indicating that the gas to be tested was measured at the 30th second of the recovery period. It is not completely desorbed from the light and gas sensing element 13, but it can be seen from the upper line of FIG. 5 that at the 30th second of the recovery period, the current value generated after sensing has risen and has returned to the value before sensing. The current value, it can be seen that in the recovery process, the contribution of the current value generated after sensing is not only the light desorbs the gas to be measured, but also the light and the gas sensing element 13 can absorb light. The optical signal can be written into the current signal, so that the current value generated after sensing can quickly rise and return to the current value before sensing.

In summary, through the combination of the light-emitting element 2 and the light and gas sensing element 13, the light-emitting element 2 is turned on after sensing. During the recovery process, the light and gas sensing element 13 can absorb light. The light signal can be written into the current signal. At the same time, the light can also promote the desorption of the gas to be measured, so that the current value generated after sensing can quickly rise and return to the current value before sensing, thereby improving the recovery efficiency , For the next sensing. Therefore, the gas sensing device of the present invention has a short current recovery time, so it can indeed achieve the objective of the present invention.

However, the foregoing are only examples of the present invention. When the scope of implementation of the present invention cannot be limited by this, all simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the patent specification still belong to Within the scope of the patent of the present invention.

1: Gas sensing device 11: The first electrode layer 111: Surface 10: Through hole 12: Second electrode layer 13: Light and gas sensor 14: Dielectric layer 15: Piezoelectric layer 20: Piercing 2: Light-emitting parts 3: glass container 31: Air intake 32: air outlet

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a schematic diagram of a first embodiment of the gas sensing device of the present invention; Figure 2 is the embodiment A schematic diagram of a gas sensing device; Figure 3 is a schematic diagram of a gas sensing device of a second embodiment of the gas sensing device of the present invention; Figure 4 is a schematic diagram of a gas sensing device of a test example; Figure 5 is a data diagram illustrating the current recovery of an embodiment of the gas sensing device of the present invention under illuminated and non-illuminated conditions; and Figure 6 is a data diagram illustrating a test example of a gas sensing device Current recovery under illuminated and non-illuminated conditions.

1: Gas sensing device

31: Air intake

2: Light-emitting parts

3: glass container

32: air outlet

Claims (5)

A gas sensing device includes: a gas sensing device, including a light and gas sensing element, used to interact with a gas to be measured, and including organic semiconductor materials; a first electrode layer connected to the light and gas sensing A second electrode layer spaced from the first electrode layer and connected to the light and gas sensing element; and a light emitting element spaced apart from the sensing device, and between the light and gas sensing element and the The gas to be measured is used to provide light that is irradiated toward the light and gas sensor and can be absorbed by the light and gas sensor. The gas sensing device according to claim 1, wherein the light emitting element is an ultraviolet lamp or a visible light lamp. The gas sensing device according to claim 1, wherein the light and gas sensing element is located between the first electrode layer and the second electrode layer, and the first electrode layer has a light-emitting element for passing light and At least one through hole contacted by the light and gas sensor. The gas sensing device according to claim 1, wherein the first electrode layer has at least one through hole; the gas sensing device further includes a layer located between the first electrode layer and the second electrode layer and connected to the first electrode layer. The dielectric layer of the electrode layer and the second electrode layer, the dielectric layer has at least one through hole communicating with the at least one through hole; the light and gas sensor and the dielectric layer are respectively located on the first electrode layer Two oppositely arranged surfaces, and the light and gas sensing element is connected to the surface of the first electrode layer and extends into the at least one through hole of the first electrode layer and the at least one through hole of the dielectric layer to connect The second electrode layer. The gas sensing device according to claim 1, wherein the organic semiconductor material is selected from poly(9,9-dioctylfluorene), 9,9-dioctylfluorene-benzothiadiazole copolymer, 9,9-Dioctylfluorene-N-(4-butylphenyl)diphenylamine copolymer, poly(3-hexylthiophene), poly(4,8-bis(5-(2-ethylhexyl) )Thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-4-(2-ethylhexyloxycarbonyl)-3-fluoro -Thieno[3,4-b]thiophen-2,6-diyl)}, poly{4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b;4, 5-b']Dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]-thieno[3,4-b]thiophenediyl)}, or , Poly{4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl- 4-(2-Ethylhexyl)-thieno[3,4-b]thiophen-2,6-diyl}.

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